1. math

    For an arithmetic sequence, a_{19} = 78. If the common difference is -3, find a_1 = (i found it to be 132) the sum of the first 57 terms =?? -I know there is a formula but i cant think of what it is

    asked by Ellie on October 25, 2009
  2. math

    Place decimal points in these numbers so that their sum is 519.654. 329 913 477 624

    asked by Kellie on August 17, 2010
  3. Math (Complex Numbers)

    Let a,b,c be complex numbers satisfying a+b+c=abc=1 and (ab+bc+ac)/3=(1/a^2)+(1/b^2)+(1c^2) The sum of absolute values of all possible ab+bc+ac can be written as (√n)/m, where n and m are positive coprime integers. What is n+m?

    asked by Mahler on May 9, 2013
  4. math

    The sides of two squares differ by 25cm while the sum of their areas is 2425cm. What is the length of the side of each square. Please answer. Thank you

    asked by Nimuel on August 14, 2016
  5. PLZ ANSWER THIS!!!! QUICK

    Suppose the lengths of the four side of a quadrilateral are represented by the expressions 3a, a+2, 2a-1, and 3a+6. write the sum of the lenghts (the perimeter), and then simplify.

    asked by yasha on October 16, 2008
  6. business

    #28 The following is a partial ANOVA table. Sum of Mean Source Squares df Square F Treatment 2 Error 20 Total 500 11

    asked by karen on January 5, 2011
  7. Analytic Geometry

    Please help me to solve this problem. Find the equation of the locus of a moving point if the sum of the slopes of the line joining it to (1,3) and (4,-2) is 1.

    asked by xavier on December 13, 2012
  8. geometry

    how can we prove that an exterior angle of a triangle has measure equal to the sum of the measures of the 2 interior angles remote from it

    asked by Laura on June 22, 2009
  9. Math check see if i;m coorrect

    In division, a problem includes a divisor, a dividend, and a(n) ______. A. product B. sum C. expression D. quotient My answer is b

    asked by Angie on August 31, 2014
  10. Algebra

    Change to fractional notation in simplest form using limit or sum of an infinite series 4.234 (34 repeating)

    asked by Emily on November 27, 2017
  11. Math

    Find two consecutive even integers such that the sum of the larger and 3 times the smaller is 234. I don't get how to put it as in equation.

    asked by Ally on October 12, 2015
  12. mathematics

    if the sum of the 6th and 7th terms of an arithmetic progression is 60 and the 3rd term is -5 find the common difference

    asked by Bella on January 11, 2015
  13. pre-calculus

    Rewrite the expression so that it involves the sum or difference of only constants and sines and cosine to the 1st power (cos 5x)^2

    asked by lina on April 3, 2012
  14. econmics

    The lump sum payment survivors receive from social security to help pay funeral and burial expenses is:

    asked by Anonymous on May 29, 2013
  15. Algebra

    2 questions I need some help with please! 1. Find the partial sum S5. an= -2n+16 2.Solve the system by triangularizing the augmented matrix and using bakc substitution. 7x=y-6 3y= -5-2x

    asked by Kris on April 17, 2013
  16. Cal II

    express integrand as sum of partial fractions and evaluate the integral. My answer is 3 ln x + -2ln(x+2). But the choices are nothing like this. What am i doing wrong??

    asked by UGH! on October 28, 2013
  17. trigonometry

    Find the sum of all of the solutions to the equation cos(2x) - sin2(x) - 1 = 0 in the interval 0 < x < 5 pi. (Use radian measure for x.) (A) 15pi (B) 0 (C) pi (D) 10pi (E) None of the above.

    asked by lan on May 12, 2011
  18. Calculus

    Consider all right circular cylinders for which the sum of the height and circumference is 30 centimeters. What is the radius of one with maximum volume. Work: V=(pi)r^2(h) h= V/(pi)(r^2) 2(pi)r + h=30 V=(pi)r^2(h) V'=2(pi)(r)h+2pi(r^2)=0

    asked by Anonymous on June 4, 2008
  19. MATH

    three consecutive terms of a geomentric progression series have product 343 and sum 49/2. fine the numbers. HOW WILL ONE SOLVE THAT? THANKS

    asked by Archiebald on July 18, 2016
  20. Pre-Calculus-check answers

    Use a sum or difference identity to find the exact value of sin 255 degrees Answer: sqrt6-sqrt2/4 Thanks

    asked by Lucy on August 30, 2008
  21. Math

    Multiply using the rule for the product of the sum and difference of two terms. Assume any variable exponents represent whole numbers. (x - y + 11)(x - y - 11)

    asked by ReRe on February 24, 2010
  22. G.p.

    Find the sum of the geometric series 1+1/2+1/4+1/8+...to 12th terms, sir how are this question answer 4095/2048

    asked by Warnar on December 8, 2016
  23. Calculus -Series3

    Find the sum of the following convergent series: (a) Ei=1 1 / (3i - 2)(3i + 1) I know that it equals: = 1/4 + 1/28 + 1/70 + 1/130 + 1/208 a= 1/4, but I can't figure out what r = 1/4 * 1/7 = 1/28, but from 1/28 to 1/70 and so on it doesn't work anymore.

    asked by Paul on September 20, 2012
  24. Math.

    Create a "magic" square (4 columns wide x 4 rows deep) using the 12 through 27. The sum of each column should be 78, each row should be 78 and the diagonals as well.

    asked by Unknown. on December 6, 2010
  25. Math

    1.calculate the sum of the infinite series S(infinity)=16+4+1+..., (1 point) A. -16/3 B.64/3 C.12 D. It does not converge 2.Which of the following formulas can be used to write 0.797979... as a fraction?

    asked by Morgan on December 6, 2018
  26. chemistry

    Could you explain this problem to me? What is the sum of the coefficients (including “1”) of the balanced equation? __CaCO3 + __NaF __ CaF2 + __Na2CO3 a.

    asked by key on January 29, 2007
  27. math

    complete to show how you can find the sum by making a ten, hundred, or thousand. ex. 9 + 5= 9+1+____ 10+_____ ________

    asked by Anonymous on September 26, 2011
  28. Math

    ÚABC ~= ÚACB BD perpendicular AC The sum fo the three angles in any triangle is 180 degree. Prove: mÚCBD = 1/2 mÚBAC

    asked by Tom on October 14, 2012
  29. statistics

    One hundred draws will be made at random with replacement from the box 1, 1, 2, 2, 2, 4... The chance that the sum will be bigger than 250 is what percent?

    asked by Amanda on October 6, 2008
  30. language

    Write these words in alphabetical order. Alphabetize them to the second letter. grim, blot, sum, build, shelf

    asked by ty on July 29, 2013
  31. Algebra

    Help! 13. Use the Distributive Property to simplify 7(6x^2 + 5x + 4) 15. Evaluate 5w^2 if w = .5 Is it 6.25? 19. Write a simplified expression to represent 5 times the sum of x and 3 increased by 10. Is it 10+5(x+3) ? Thanks -MC

    asked by mysterychicken on March 30, 2010
  32. Algebra

    Find the sum of (-3a+4cd-6ac)-(7ab-9cd-10ac)+(-8ab+cd-2ac)-(9ab-5cd+CD)

    asked by Gler on June 15, 2016
  33. algebra

    Suppose the lengths of the four side of a quadrilateral are represented by the expressions 3a, a+2, 2a-1, and 3a+6. write the sum of the lenghts (the perimeter), and then simplify.

    asked by yasha on October 16, 2008
  34. Algebra

    Help!! 13. Use the Distributive Property to simplify 7(6x^2 + 5x + 4) 15. Evaluate 5w^2 if w = .5 19. Write a simplified expression to represent 5 times the sum of x and 3 increased by 10. Is it 10+5(x+3) ? Thanks -MC

    asked by mysterychicken on March 30, 2010
  35. sum fun (math)

    find a quick and easy method to compute the sum of the first 100 counting numbers (no calculators allowed)

    asked by Jenny on January 27, 2010
  36. Statistics

    The residual sum of the squares is the numerator portion of the formula for the variance of y about the regression line. True False

    asked by Mike on November 6, 2012
  37. algebra

    Please can someone help me? Thanks! Find the least common multiple of each pair of polynomials: 12x^2-6x-126 and 18x-63 Simplify each sum: 5y+2 2x-4 ---- + ----- xy^2 4xy

    asked by Elizabeth on May 7, 2007
  38. Trigonometry

    Let S be the sum of all the possible values of sin x that satisfy the following equation: 5-2cos^2(x)-7sin(x) = 0 S can be written as a/b, where a and b are coprime positive integers. What is the value of a + b?

    asked by Tony on March 6, 2013
  39. Statistics

    The residual sum of the squares is the numerator portion of the formula for the variance of y about the regression line. True False

    asked by Mike on November 5, 2012
  40. trig

    Find the sum of all of the solutions to the equation cos(2x) − sin2(x) − 1 = 0 in theinterval 0 < x < 5 pi. (Use radian measure for x.) (A) 15pi (B) 0 (C) pi (D) 10pi (E) None of the above.

    asked by minh on May 7, 2011
  41. Math

    Kate is 4yrs older than Margaret . In 7yrs the sum of their ages will be 70. How old are they now. How do you find kates age using mArgarets

    asked by Amy on February 10, 2011
  42. math

    a certain sum of money amounts to rs8820 in 2yrs and to rs9261 in 3yrs at compd interest.find rate%

    asked by anoop on July 31, 2017
  43. math

    Carrie said that the best estimate for the sum of the heights is 10,000 feet. Explain hoe you would check her answer to see whether it is reasonable.

    asked by Inayah on October 1, 2011
  44. HELP WITH ALGEBRA!!!!!!!

    Suppose the lengths of the four side of a quadrilateral are represented by the expressions 3a, a+2, 2a-1, and 3a+6. write the sum of the lenghts (the perimeter), and then simplify.

    asked by yasha on October 16, 2008
  45. Algebra

    I am thinking of two numbers. The first number added to the second number is 5. Twice the first number added to twice the second number is 10. What are the numbers. ????? 1&4

    asked by Dylan on April 23, 2018
  46. 7th grade math

    A restaurant donates 2 cans of soup to charity for every 9 bowls of soup it sells. The number of cans of soup donated by the restaurant is proportional to the total number of bowls of soup sold. Which equation represents the relationship between b, the

    asked by Liz on March 29, 2013
  47. maths linear eqautions

    i have a number of sweets in a bag. if i removed three of them and divided the number remaining by 4, i would have two fewer than if i removed 7 and divided the number remaining by 3. How many sweets do i have (N-3)/4 = (N-7)/3 +2 check my thinking. I see

    asked by fussiilat on September 14, 2006
  48. chem experiment:

    You are required to design an experiment to test Hess's law using the combustion of ethanol. Write a brief design for this experiment. What I wrote as my answer: Hess’ Law: is the algebraic addition of chemical equations yields a net equation whose

    asked by rob on May 17, 2007
  49. chemistry - atoms

    Understanding Chemical Bonding This is a short activity to introduce you to the concept of chemical bonding. In this activity, you will take the number of your birth month as your atomic number. Using this information, you will be able to determine the

    asked by Mel on September 11, 2008
  50. VB

    I am new here; say to everyone first. Here is the a question for coding list box; it has two part: first part: Create a project that stores personal information for a little electronic "black book"; the fields in the file should include name, phone number,

    asked by austin on November 16, 2011
  51. physics

    check which of the following modifications to a solenoid would be most likely to decrease the strength of its magnetic field? a. removing its iron rod core and increasing the number of coils b. increasing the current and reducing the number of coils c.

    asked by physics on March 12, 2009
  52. Answers check and help!

    d. Calculate the mean square for 1) gender, 2) marital status, 3) interaction between gender and marital status, and 4) error or within variance. e. Calculate the F ratio for 1) gender, 2) marital status, and 3) interaction between gender and marital

    asked by Vanessa on September 24, 2013
  53. statistics

    Can someone provide me with some assistance in answering this question.. A company manufacturers batteries in BATCHES of 18 and there is a 3% rate of defect. Find the standard deviation for the number of defects per batch. The probability of a defect is p

    asked by john on August 5, 2007
  54. Math

    Kate said to Liam, “If you roll a 5 on a number cube, you win. If I get a head on a coin toss, I win.” Is the game fair or unfair? Explain. a.No; P(5) and P(Heads) are not basically close. b.No; Heads is not an option on a number cube. c.Yes; P(5) and

    asked by Ms.Sue on February 25, 2019
  55. trig

    prove that there exists no smallest possitive real number dose there exist a smallest positive rational number given a real number x, does there exist a smallest real y>x?

    asked by Sarah on August 28, 2012
  56. Poem Help Needed

    This is a poem by John Berryman that I am supposed to analyze and I am completely confused by. If anyone has any observations or ideas about the main idea of the poem, PLEASE help me out! "The Traveller" They pointed me out on the highway, and they said

    asked by Belinda on April 8, 2007
  57. Chemistry

    For another picnic, you want to make hamburgers with pickles, again without having any left over. You need to balance the number of packages of buns (which usually contain 8 buns) with the number of packages of hamburger patties (which usually contain 12

    asked by Becca on January 19, 2015
  58. Math

    If you told someone that the greatest depth of Lake Superior is 1333ft would you be expressing a number similar to mode, median, mean or range? That would be the range. The mode is the numbers that appear most often. Median is the middle number and mean is

    asked by Connor on April 23, 2007
  59. Algebra 1

    Julie subscribes to a sports magazine and a fashion magazine. She received 24 issues this year. The number of fashion issues is 6 less than twice the number of sports issues. Define the variables, and write a system of equations to find the number of

    asked by Gabbi on February 17, 2014
  60. Algebra

    Andy has 145 coins in his coin bank. THe number of 5-denomination coins is 10 more than twice the number of 10-denomination coins. The difference between the number of 1-denomination coins and 5-denomination coins is 5 more than the number of

    asked by Ashley Kate on January 6, 2014
  61. Easy Math

    The number of positive integers that are less than 500 and that are not divisable by 2 or 3 is? There are 250 divisible by 2, 166 divisible by 3 and 83 divisible by both. So 250 + 166 - 83 = the numbers divisible by 2 or 3, without double counting.

    asked by Gina on October 7, 2006
  62. Math

    I have three more questions I do not understand. 1. Two points (-1,1) and (3,-2) are graphed on a coordinate plane. What is the shortest distance between the points? A. 3 B. 4 C. 5 D. 7 I have no idea how to do this. 2. Which expression represents the nth

    asked by Sammy on April 18, 2011
  63. algebra

    1. write an algebraic expression for the word phrase: the quotient of r and 12 a.r * 12 b.r/12**** c.r-12 2. write a word phrase for the algebraic expression: 2t - 9 a.nine fewer than two times a number t***** b.nine fewer than two times a number t c.nine

    asked by someone on August 23, 2015
  64. Hard Math :(

    2. What answer represents this number in scientific notation? 0.00000916 a. 916 x 10^-8 b. 9.16 x 10^-6 c. 916 x 10^8 d. 9.16 x 10^6 3. What is this number in standard form? 6.8 x 10^-4 a. 5,750,000,000 b. 575,000,000,000 c. 0.00000000575 d. 0.575000000000

    asked by Dude on September 10, 2012
  65. 6th grade Math

    1. At Saturday's football game, there were 45 more than half the fans at Fridays game. Assuming there were "x" fans at Friday's game, what expression represents the number of fans at Saturday's game? = 1/2x + 45 (1/2 times x plus 45) 2. What is the

    asked by Jared on November 8, 2018
  66. Algebra 2

    PLEASE HELP WITH THIS-ITS DUE APRIL 5TH, 2011!!! During a past epidemic, the number of infected people increased exponentially with time, or f (t) = ab^t , where f is the number of infected people at time t, in days. Suppose that at the onset of the

    asked by Lindsey on March 27, 2011
  67. Math

    An apprentice Carpenter has designed a wooden coffee table. he expects to sell 25 such tables for 95$ each at an upcoming artisan market. by conducting a survey, he determines that for each $2 reduction in the price of the table, he will likely gain three

    asked by lola on May 14, 2013
  68. algebra 1

    A manufacturer is cutting plastic sheets to make rectangles that are 11.125 inches by 7.625 inches. Each rectangle’s length and width must be within 0.005 inches. A. Plot the acceptable range of lengths on the number line that follows: B. Write an

    asked by mark on November 24, 2013
  69. Chemistry

    An element has three stable isotopes. One has a mass number of 63 and an abundance of 50%. The second has a mass number of 65 and an abundance of 30%. The third has a mass number of 67 and an abundance of 20%. Calculate the relative atomic mass of this

    asked by Robert on September 24, 2016
  70. math

    Terry bought some gum and candy. The number of packages of chewing gum was one more than the number of mints. The number of mints was three times the number of candy bars. If gum was 6 cents a package, mints were 3 cents each, and candy bars were 10 cents

    asked by john on January 2, 2018
  71. math

    Terry bought some gum and candy. The number of packages of chewing gum was one more than the number of mints. The number of mints was three times the number of candy bars. If gum was 6 cents a package, mints were 3 cents each, and candy bars were 10 cents

    asked by john on December 25, 2017
  72. Science need help

    What is the independent variable? 1 is that the correct answer help plz Sue is setting up an experiment to test whether fly maggots select a dark or a brightly lit environment. She sets up a chamber in which there is a gradient in light intensity from one

    asked by john on December 11, 2013
  73. Maths

    Please help. I completed 1-6 but these 4 are hard; the wording confusing. 1) Jane is playing a game of Monopoly, if she throws six on her next turn she will land on community chest. If she throws eight she will land on Mayfair with a hotel (owned by

    asked by Barry on June 29, 2017
  74. math

    A pair of dice is rolled, and a number that appears uppermost on each die is observed, Refer to this experiment and find the probability of the given event. (Enter your answer as a fraction)The sume of the numbers ia an add number.

    asked by Maria on April 21, 2012
  75. Math

    what is 0.000750 in scientific notation? a.75 x 10^-4 b. 7.5 x 10^-3 c.7.5 x 10^-4 d. 7.5 x 10^-5 what is 27/6 written as a decimal? a 4.2 b 4.3 c 4.4 d 4.5 what is 8.57 x 10^-4 in standard form? a.85000 b. 0.00857 c. 8570000 d. 0.000857 which of the

    asked by Sandra on October 17, 2018
  76. PSY 369

    Studies have shown that in large American cities, there is a relationship between the number of violent crimes and the number of stores that sell pornography depicting violence. Is this a positive or negative correlation? Provide an explanation.

    asked by Jay on June 15, 2013
  77. math

    The t-shirts for the fundraiser will cost $4.00 to make and there is a $25.00 delivery fee. There are two sized wristbands; a large one that will cost $5.00 to make, and a small one that will cost $3.00. 1. Write an expression to represent the student

    asked by anonymous on June 2, 2014
  78. CHEMISTRY

    what is the symbol for chromium (II) sulfate? You mean the formula? CrSO4 yes! thanx!!!!!! do u know how to find the number of molecules or atoms in a mole? The number of atoms in a mole is called Avogadro's number, the value of which is approximately 6.02

    asked by INEEDHELP!!! on December 4, 2006
  79. Algebra HELP

    Can someone please help me with this Algebra problem. The equation y= -1777x + 27,153 can be used to predict the number of y of gun deaths in the U.S. x years after 2000, that is, x=0 corresponds to 2000, x=2 corresponds to 2002, x-6 corresponds to 2006,

    asked by Susan on May 27, 2010
  80. Math

    Can someone please help me with this Algebra problem. The equation y= -1777x + 27,153 can be used to predict the number of y of gun deaths in the U.S. x years after 2000, that is, x=0 corresponds to 2000, x=2 corresponds to 2002, x-6 corresponds to 2006,

    asked by Susan on May 27, 2010
  81. linear optimization

    During a summer session a student enrolls in two courses, psychology for four hours and engineering for three hours. The student wants to use the available time to amass the largest number of grade points (numerical grade multiplied by the number of

    asked by gemicia on December 29, 2013
  82. Math 1

    write an equation that represents the following situation. Let x= the number of adults. Your equatin should start with "1220=" and use x as the only variable.. The number of students attending the fall play was 150 more than the number of adults attending.

    asked by JJ on October 1, 2014
  83. math

    2. What answer represents this number in scientific notation? 0.00000916 a. 916 x 10^-8 b. 9.16 x 10^-6 c. 916 x 10^8 d. 9.16 x 10^6 3. What is this number in standard form? 6.8 x 10^-4 a. 5,750,000,000 b. 575,000,000,000 c. 0.00000000575 d. 0.575000000000

    asked by chase on September 10, 2012
  84. math

    2. What answer represents this number in scientific notation? 0.00000916 a. 916 x 10^-8 b. 9.16 x 10^-6 c. 916 x 10^8 d. 9.16 x 10^6 3. What is this number in standard form? 6.8 x 10^-4 a. 5,750,000,000 b. 575,000,000,000 c. 0.00000000575 d. 0.575000000000

    asked by chase on September 10, 2012
  85. Math

    5.Jack participated in a 6 day bike marathon of 430 kilometers. He biked 90 kilometers on each of the first 4 days and y kilometers on the fifth day. Which equation can be used to find b, the number of kilometers Jack biked on the sixth day?

    asked by Jerald on June 4, 2013
  86. MATH

    The number of students who ride a bike to school is 15 more than the number of students who walk to school. The letter s represents the number of students who walk to school. Which of these shows the number of students who bike to school? A. s – 15 B. 15

    asked by PLEASE HELP ME!!!!!!!!!!!!!!!!!!!!!!!!PLEASE!!!!!! on March 29, 2012
  87. Math

    1. –(10)^–1 (1 point) –1/10*** -1/-1^10 1/10 10 2. 1/c^-5 (1 point) c^5 5c –c^5*** –5/c 3. What is the value of y^-5/x^-3 for x = 2 and y = –4? (1 point) 10/3 128 -1/128 –128*** 4. Is the number written in scientific notation? If not,

    asked by Bethany on April 22, 2016
  88. Urgent math

    population growth model. Can anybody please help me out in trying to solve this problem? It's my homework and I don't seem to understand what I am getting. The count in a culture of bacteria was 400 after 2 hours and 25,600 after 6 hours. (a) What is the

    asked by Lydia on August 3, 2015
  89. 7th grade math (probability)

    I'm posting corrections from yesterday in addition to new ones. Still not sure how to answer #4. 2. Edwin rolls a number cube and then spins a color from a color card (red, yellow, blue, green, white). What is the probability that he will roll an even

    asked by Alexis on May 6, 2015
  90. Maths Please Help

    Alex and Bella play the following game. They first choose a positive integer N, and take turns writing numbers on a blackboard. Alex starts first, and writes the number 1. After that, if the number k is on the board, the next player may write down either

    asked by Mathslover on May 22, 2013
  91. precalc

    #1 For what positive numbers will the cube of a number exceed four times its square? #2 For what positive numbers will the cube of a number be less than the number? thanks

    asked by Rebekah on October 21, 2012
  92. Precalc

    #1 For what positive numbers will the cube of a number exceed four times its square? #2 For what positive numbers will the cube of a number be less than the number? thanks

    asked by Rebekah on October 21, 2012
  93. math/ ratio

    there are 45 fruits. 21 are bananas, 15 are pineapples, and the rest are papayas. what is the ratio of the number of bananas to the number of pineapples to the number of papayas?

    asked by charylle on January 5, 2015
  94. math

    Consider the given statements. 1. Every prime number is odd. 2. There are 8 prime numbers between 10 and 40. 3. There are 11 composite numbers between 0 and 20. 4. The number 4 is the smallest even composite number.

    asked by angela on July 15, 2014
  95. math

    The number of girls in the choir is 4 times the number of boys in the choir. The total number of students in the choir is 60. How many girls are in the choir?

    asked by steve on November 9, 2015
  96. chemistry

    For another picnic, you want to make hamburgers with pickles, again without having any left over. You need to balance the number of packages of buns (which usually contain 8 buns) with the number of packages of hamburger patties (which usually contain 12

    asked by Anonymous on October 1, 2013
  97. Algebra

    Varun takes a certain number of Rotis during lunch but always wasted half a roti. Rosa takes half the number of Rotis as Varun, and always finishes her share .after 20 days, if the number of Rotis that were consumed during lunch by them together is 110

    asked by Purva on March 19, 2017
  98. college algebra

    The number of motor vehicle deaths in the US was 49,391 in 1988 and 46,300 in 1990. If the trend stays the same, what will be the number of deaths in 2005? Thank you for any help!!!

    asked by jenny on October 14, 2008
  99. math

    Use the formula to solve for c. Choose the right answer. Amount Financed (m) = $275 Number of Payments per year (y) = 12 Number of Payments (n) = 18 APR (I) = 12%

    asked by Anonymous on April 20, 2017
  100. Math

    My home work asks "what is the five number summery of a datta set? How is it used to mAke a box plot?" But i frogot what a five number summery is please help.

    asked by Magiemay on April 25, 2013