Saturday

October 10, 2015
Number of results: 41,067

**math**

What is the definition for an EXPRESSION ? An expression in English can be a short sentence, or a sentence fragment. Take a hike. Go figure. What's up? Whatever. In math, an expression is again a fragment, it can be complete or not complete. 2x + 1 Sin^2(2x) + 2 e^(2x + ...
*September 19, 2006 by gio*

**Mathematics**

In the problems 1 to 3, find the present value of the given (ordinary) annuity. 1. $3500000 every 6 months for 5 years at the rate of 16% compounded semi-annually. 2. $7000000 per month for 10 months at the rate of18% compounded monthly. 3. $1700000 per year for 5 years at the...
*June 22, 2010 by Gibbons*

**statistics**

1. Use the following information about a group of college students: Fifty percent are taking Algebra. Sixty percent are taking Biology. Thirty percent are taking both Biology and Algebra. A student from the group is selected at random, calculate the following: a) The ...
*September 18, 2011 by Ahmad*

**Mathematics**

A car X left town A for town B at the same time that another car Y left town B for town A, each travelling at constant speed. They met 80 minutes later and car X arrived at town B 36 minutes after car Y reached town A. How long did it take car X to reach town B?
*July 9, 2015 by Henry*

**Mathematics **

The distance to the nearest 100,000 km from the earth to the moon is given as 400,000 km. The average speed to the Nearest 500km/h is 3500km/h. Calculate the least and greatest time it takes the rocket to reach the moon I figured out the formula speed = distance / time but ...
*March 31, 2015 by Fay*

**math**

In each case, consider what you know about the distribution and them explain why you would expect it to be or not to be norally distributed. a. The wealth of the parents of students attending your school b. The value that a group of fourth-grade students would give for the ...
*September 12, 2010 by Renee*

**pre-calculus**

Solve eacy system of inequalities. If the system has no solution, say that it is inconsistant. x -y -z = 1 2x +3y +z = 2 3x +2y = 0 add the top two equations. 2x+2y =3 That is inconsistent with the last equation.
*October 24, 2006 by Erica*

**Mechanics**

How do you dereive equilibrium equations for a 2-D pi/3 section of a circle in polar coords? There are stresses & shears. (Eight total, one stress & one shear on each side)
*September 29, 2007 by Brian*

**Differential Equation**

Hello everyone. I was wondering if anyone knows a site that could help me with the homework free online...with Differential equations. it would be great. I need help on in big time thank you
*October 22, 2008 by mary*

**calculus**

is y = x^3 a solution to the differential equation xy'-3y=0?? how do i go about solving this??? also, is there a trick to understanding differential equations? i'm really struggling with this idea, but i'm too embarassed to ask my professor for help.
*December 1, 2008 by Kenneth*

**chemistry**

I don't understand net ionic equations; for example, when you're given Pb(NO3)2(aq)+2LiCl(aq) how do you know that in the product Pb has to be paired with Cl2 and Li with NO3 to make PbCl2(s)+2LiNO3(aq)?
*January 7, 2009 by GP*

**chemistry: equations and reactions**

identify the products when the following substances decompose: 1) binary compoound 2) metallic hydroxide 3) metallic carbonate 4) the acid H2SO3
*February 12, 2009 by Stephanie*

**chemistry**

Write the complete balanced molecular, ionic,and net ionic equations for the reaction of nickle II chloride + sodium phosphate. Which product,if any, is a precipitate?
*December 3, 2009 by LaLa*

**Calculus**

"Find the volume of the solid generated by revolving the region bounded by the graphs of the given equations about the indicated lines: y = 2x^2 y = 0 x = 2 About the line y = 8"
*April 18, 2010 by Stuck*

**college differential equations**

Find two linearly independent power series solutions to the diffrential equation. State the first 3 therms of each series: 2x^2y''+xy'-(1+2x^2)y=0
*July 28, 2010 by Justin*

**math/equations**

Hi. I am having some issues with this one. Give the equation of the line that is perpendicular to the line y=x+6 and passes through point (0,-4). Thank you so very much!!!
*July 29, 2010 by amy*

**Math**

What does it mean if a line in R^3 is parallel to the xy-plane but not to any of the axes. I really don't know what this means in terms of how the parametric and symmetric equations of the line should look. Please help.
*October 27, 2010 by Kate*

**Math**

What does it mean if a line in R^3 is parallel to the xy-plane but not to any of the axes. I really don't know what this means in terms of how the parametric and symmetric equations of the line should look. Please help.
*November 2, 2010 by Kate*

**calculus**

Find the volume of the solid generated by revolving the region bounded by the graphs of the equations and/or inequalities about the indicated axis. x = y(25 − y2)^1/2 x = 0 the y-axis
*February 2, 2011 by Morgan *

**Andy**

Name: Lesson 3 Assignment.Instructions Explain the differences between solving these two equations: •log3(x - 1) = 4 and log3(x - 1) = log34. I think it has to do with the formulas
*February 8, 2011 by andy*

**Chem**

Write the balanced net ionic equations for the reaction of a) added H+ and B) added OH- with the components of the acetic acid/sodium acetate buffer solution:
*February 9, 2011 by Bubba*

**Maths**

Basically there is this graph with the equations: x = cos t + 2 sin t and y = sin 2t (o<t<pi) I am asked to find the x-co-ordinates of A, B and D. All these points cross the x-axis, therefore y=0. How do I go about this?
*March 6, 2011 by Jennifer*

**in-organic chemistry**

provide balanced equations that represent the thermal decomposition of sodium nitrate and calcium nitrate; compare and comment on the products of each reaction.
*August 27, 2011 by bulelwa*

**precalc**

a circle is formed with a center (-3,5) and a radius.of 4 write the circle as a pair of parametric equations. then show how you can eliminate the parameter to return to the rectangular form
*April 26, 2013 by gggggg*

**biorganic**

equations of thereactions of both maleic acid and fumaric acid with (a) bromine (b) hydrogen chloride (c) catalytic hydrogenation.name the products of these reaction
*October 31, 2013 by debbie*

**Differential Equations**

Solve dy/dx = y/(2y-x) using rational substitution (using v=y/x) with the initial condition y(0)=1. I solved this problem and found C (the constant) to be undefined. That is not the correct answer.
*February 15, 2014 by Liz*

**Chemistry**

Determine [Zn2 ], [CN–], and [HCN] in a saturated solution of Zn(CN)2 with a fixed pH of 2.640. The Ksp for Zn(CN)2 is 3.0 × 10–16. The Ka for HCN is 6.2 × 10–10. I need to know what equations to use to find the answer not just how to get it
*February 23, 2014 by Sonya*

**math (Matrix)**

solve the equations by using a) the adjoint matrix b) elementary row operations i) x+y+z=6 2x-y+z=3 x+4y-z=6 ii) 3p-3q+r=1 -3p+5q-2r=-1 p-2q+r=3 iii)-12a+b+17c=-14 2a-b+3c=5 8a+b-13c=-3 thanks sir/madam
*April 15, 2014 by shahira*

**maths (matrix)**

solve the equations by using a) the adjoint matrix b) elementary row operations i) x+y+z=6 2x-y+z=3 x+4y-z=6 ii) 3p-3q+r=1 -3p+5q-2r=-1 p-2q+r=3 iii)-12a+b+17c=-14 2a-b+3c=5 8a+b-13c=-3 thanks sir/madam
*April 15, 2014 by shiha*

**math (Matrix)**

solve the equations by using a) the adjoint matrix b) elementary row operations i) x+y+z=6 2x-y+z=3 x+4y-z=6 ii) 3p-3q+r=1 -3p+5q-2r=-1 p-2q+r=3 iii)-12a+b+17c=-14 2a-b+3c=5 8a+b-13c=-3 thanks sir/madam
*April 15, 2014 by MARYSE*

**Math **

Use back substitution to solve the system of linear equations x-2y+z=8 y+z=5 z=2 **I tried to solve it eventho im still confused/lost. 1=3 idk ugh
*June 17, 2014 by Anonymous*

**Math**

So I've been working on solving this system by addition/subtraction and I just can't get the right answer. Her is the system of equations I was given to solve by add/sub: 3x – y = –12 x + 2y = –18
*July 20, 2014 by jririfi*

**Pre-Calc/Trig...**

Am i correct? It is possible for a system of linear equations to have no solutions. True <-- False i think it's true, if the lines are parallel?
*October 3, 2014 by Anonymous*

**college chem**

A 1.10g- sample contains only glucose and sucrose . When the sample is dissolved in water to a total solution volume of 25.0ML , the osmotic pressure of the solution is 3.78atm at 298K a.What is the percent by mass of glucose in the sample? b.What is the percent by mass of ...
*January 25, 2010 by mm*

**Mathematics**

A survey in a class shows that 14 of the student plays football,10 plays handball and 5 play both football and handball . How many student are there in a class if every one plays at least one of this game.
*April 26, 2012 by Afuape*

**math**

Find the y-intercept and the x-intercept for the equations -6x+y=10
*May 7, 2010 by lana*

**calculus**

Solve the equations i) log2(x + 2) + log2 x = 3. ii) 25^x + 5^x+1 + 6 = 0.
*July 26, 2011 by MSM*

**Geometry**

Find the x- and y- intercepts for each equations. What is the x- and y- intercepts? y= -2x + 8
*August 28, 2011 by Kara*

**math**

5th grade math equations
*September 25, 2012 by ericka*

**m**

Solve the equations. (a) 2D + 3 = 13 D = _____ (b) 12E - 3 = 0 E = _____
*December 21, 2012 by Regina M*

**algebra**

CAN SOMEONE PLEASE HELPPP!? I NEED HELP IN ALGEBRA, SIMPLIFYING RADICALS! SIMPLIFY THE SQUARE ROOT OF 45a SQUARED!
*May 20, 2008 by I NEED HELPPPP!**

**Math (Algebra/Pre-Algebra)**

A book has been discounted 20% and now sells for $15. How much did it cost before the discount?
*June 4, 2009 by Samantha*

**Algebra Question**

How do I write A-1 The minus one is small and at the top but I am new at algebra and this is the first time I had to use this.
*December 21, 2009 by mike*

**Algebra**

What are intersections and unions (in algebra). Also, what are complements? And what does MATH stand for in terms of sets? Please answer quickly. Thanks!
*September 21, 2011 by Jena*

**Math (Algebra/Pre-Algebra)**

Which equation is an identity? a. 3x - 9 = 3x b. 4p + 7 = 7 + 4p c. 2w = 0 d. 5k = 5
*June 4, 2009 by Samantha*

**algebra**

can anyone tell me a few site good for algebra 1a?
*October 27, 2009 by N~*

**math/algebra**

I need help with an algebra problem, please help. y=1/2x-4. Thank you.
*January 18, 2011 by Ever*

**ALGEBRA 2**

WHAT IS THE RIDDLE TO ALGEBRA WITH PIZZAZZ WORK SHEET 56??
*October 13, 2011 by ANGELO*

**Algebra**

In Algebra terms, what does "restrict the variables" mean?
*October 14, 2011 by Emma*

**algebra**

algebra with pizzazz!In music,what does allegro means?
*September 13, 2012 by Mary*

**algebra**

PLEASE help me with my questions below in algebra. i am desperate!!!
*March 3, 2013 by sam help i just switched schools & i am LOST!*

**Algebra**

What is the riddle to Algebra with Pizzazz worksheet number7?
*November 17, 2013 by Anonymous*

**engineering mathematics 1**

your father wants to fence a rectangular area in your backyard for a garden. one side of the garden is along rhe edgeof the yard is already fenced, so you only need to build a new fence along the other 3 sides of rectangle. if you have 80 meter of fencing available, what ...
*April 17, 2014 by athira*

**Social Psychology**

“Self-concept differs from self-efficacy in that self-efficacy is a context-specific assessment of competence to perform a specific task […] A student may feel highly efficacious in mathematics but without the corresponding positive feelings in self-worth […]” (ibid, 561). ...
*August 21, 2011 by Sharon*

**Analytical chemistry**

A dilute perchloric acid solution was standardized by dissolving 0.2445 g of primary standard sodium carbonate in 50 mL of the acid, boiling to eliminate CO2, and back-titrating with 4.13mL of dilute NaOH. In a seperate titration a 25mL portion of the acid required 26.88 mL of...
*August 1, 2013 by Gloria*

**Physics**

In the approximation that the Earth is a sphere of uniform density, it can be shown that the gravitational force it exerts on a mass m inside the Earth at a distance r from the center is mg(r/R), where R is the radius of the Earth. (Note that at the the surface and at the ...
*March 9, 2011 by Amelie*

**math**

write an equation for the parabola with focus (1,3) and vetex (0,3) See the paragraph Analytic Geometry Equations. You will have a choice of equations, you did not state whether the axis of symettry was parallel to x or y axis. http://en.wikipedia.org/wiki/Parabola that was ...
*August 12, 2007 by Marissa*

**Mathematics**

Express the Complex Number -1-i in polar form. how is complex no expressed in polar form? what is polar form of complex no? Please help
*March 3, 2014 by Sykox*

**math**

Consider the distribution of mathematics SAT scores of students in honors calculus at a liberal arts college. What would you expect the shape and variation of the distribution to be? A. Symmetric with little variation B. Symmetric with large variation C. Skewed right with ...
*May 28, 2015 by scoobs2usa*

**PROBLEM SOLVING IN MATHEMATICS**

there are two prime numbers between 100 and 199 such that the ten digits is a prime number, the ones digit is a prime number and the tens and ones digits taken together are a 2 digit prime number. find the sum of these 2 prime number.
*October 6, 2011 by alya*

**math**

Solve the system of equations: x - y - z = 2 x + 2y - 2z = 3 3x - 2y - 4z = 5 I know how to do the whole process, but sometimes I make careless errors that I never catch when I go over my work. This is the answer I worked out: x = 5 y = 1 z = 2 could somebody please let me ...
*May 5, 2008 by Jennifer*

**physics**

If the angular quantities θ,ω,α were specified in terms of degrees rather than radians, how would the kinematics equations for uniformly accelerated rotational motion have to be altered?
*April 11, 2010 by Charlie*

**calculus **

Find the area under one arch of a cycloid described by the parametric equations x=3(2theta -sin2theta) & y=3(1-cos2theta) use 0 and pi for te limiting values of. A.9pi B.18pi C.27pi D.36pi
*March 13, 2011 by anon*

**college chemistry**

Guys i really need help in these three problems. If someone could explain how to do this i would appreciate it! complete and balance the following equations 1. SO3^2- + Cu^2+ --> SO4^2- + Cu^+ 2. Cr +Cu^2+ ---> CrO4^2- + Cu^+ 3. MnO2 + Ag^+ ---> MnO4^- + Ag
*February 14, 2012 by Keisha*

**chem**

Write balanced equations for the following reactions. (Use the lowest possible coefficients. Omit states-of-matter in your answer. 238 U 92 (á, n) 241 Pu 94 sorry teh formating is off
*August 31, 2012 by sara*

**Earth Science**

Use angular momentum arguments to describe why a parcel of air moving from the equator towards the North Pole will be deflected to the east. It may be helpful to show equations in your response.
*November 20, 2014 by Sarah*

**Earth Science**

Use angular momentum arguments to describe why a parcel of air moving from the equator towards the North Pole will be deflected to the east. It may be helpful to show equations in your response. THANKS
*November 20, 2014 by Sarah*

**english**

Mrs. Sue or anybody can you help me with this question please?? Create a paraphrase of the following sentence from “The Cold Equations”: She held the letters out to him. "Will you take care of these and see that they're enveloped and mailed?" pls help me
*September 5, 2015 by oscar*

**mathematics - sinusoidal curves**

Owen is jumping on a trampoline. When his feet hit the deck of the trampoline, the material depresses to a minimum height of 2cm. On average, Owen is reaching a maximum height of 200cm every 10 seconds. Determine the equation of a sinusoidal function that would model this ...
*May 5, 2012 by arnab*

**PROBLEM SOLVING IN MATHEMATICS**

the average age of a group of teachers and student is 20. the average age of the teachers is 35. the average age of the students is 15. what is the ratio number of teacher to number of students ?
*October 13, 2011 by alya*

**Math (Fourier)**

I want to self-study Fourier Transforms followed by signal analysis and Wavelets. I am considering buying the books: "Fourier Analysis: An Introduction" and "A First Course in Fourier Analysis". My question is, are these at my level or are they over my head? Are these books ...
*August 21, 2009 by Sean*

**algebra**

An algebra book weighs 6 oz less than twice as much as a grammar book. If 5 algebra books weigh the same as 8 grammar books, how much does an algebra book weigh?
*October 19, 2011 by Anonymous*

**Algebra**

A company has two printers. Printer A prints a pages per minute, and Printer B prints b pages per minute. When Printer A prints for 3 minutes and Printer B prints 5 minutes, a total of 70 pages are printed. When Printer A prints for 6 minutes and Printer B prints for 9 minutes...
*March 31, 2013 by Angie*

**Mathematics**

At football practice, players do a 20-minute warm-up before starting their practice drills. After the practice drills, they do a 10-minute cool-down. The expression 20+d+10 describes the length of practice, where d is the number of minutes the practice drills last. How long, ...
*June 1, 2011 by HELP*

**College Algebra**

a paper manufacturing company recycles paper, cans and other sheet metal. the profit on the paper is $500 and the profit on the cans is $350 per pound A) write the objective function that models the daily profit B) the manufacture is bound by the following constraints , ...
*March 6, 2015 by meri*

**College Algebra**

a paper manufacturing company recycles paper, cans and other sheet metal. the profit on the paper is $500 and the profit on the cans is $350 per pound A) write the objective function that models the daily profit B) the manufacture is bound by the following constraints , namely...
*March 6, 2015 by meri*

**MATH Prob.**

In each case, consider what you know about the distribution and then explain why you would expect it to be or not to be normally distributed. a. The wealth of the parents of students attending your school b. The values that a group of fourth-grade students would give for the ...
*August 11, 2009 by Twg*

**College Physics**

n the approximation that the Earth is a sphere of uniform density, it can be shown that the gravitational force it exerts on a mass m inside the Earth at a distance r from the center is mg(r/R), where R is the radius of the Earth. (Note that at the the surface and at the ...
*March 8, 2011 by Amelie*

**Algebra **

Joe and Theresa want to paint their living room. From past experience they know that Joe can paint the room in 6 hours and Theresa can paint it in 10 hours. How long will it take them if they work together? Mower A can cut a field in 6 hours and Mower B cut the same field in 2...
*March 5, 2014 by Chelsey*

**mathematics**

1.)Sin^-1(x)+Sin^-1(y)+Sin^-1(z)= pie Prove that X.root(1-y^2)+y.root(1-x^2)+z.root(1-z^2)=2xyz 2.)tan^-1(yz/xr)+tan^-1(zx/yr)+tan^-1(xy/zr)=pie/4 Prove that x^2+y^2+z^2=r^2 Tomorrow is my exam.please give me answer as soon as possible.
*May 23, 2013 by edward*

**mathematics**

THE 1ST, 3RD AND 9TH TERM OF A LINEAR SEQUENCE A.P ARE THE 1ST THREE TIMES OF G.P. IF THE 7TH TERM OF THE LINEAR SEQUENCE IS 14. CALCULATE (A) 20TH TERM OF THE LINEAR SEQUENCE (B) SUM OF THE 1ST, 12TH TERM OF THE G.P
*March 5, 2015 by AYOMIDEY*

**Algebra 1A**

describe what the graph of interval -4, 10 looks like? This is for math 166 algebra 1A I dont understand how to answer this question, please help me!
*November 29, 2008 by Julissa*

**algebra**

Since I am new to the algebra and do not fully understand it, I am not sure how to answer the following question. Hope you can help. thanks how do you know when an equation has infinitely many solutions
*August 9, 2010 by Ziggy*

**Algebra 2**

What is the slope of the line that passes through the points (-2, 4.15) and (1, 1.24)? Here's my work: m= y2-y1 / x2-x1 m+ 1.24-4.15 / 1 - (-2) m= -2.91/3 Is my answer correct? I really appreciate your help! Algebra isn't the easiest for me
*September 4, 2013 by Josh*

**Math**

I'm an on-going 8th grader, and I'm taking a class for Algebra 2. What should I expect that is different from Algebra 1? P.S. I've taken Geometry online.
*June 8, 2014 by Sheenybeany*

**algebra**

what do the words, "express m in terms of n" mean? which wors would be considered the input variable into the expression? algebra 1 homework
*August 12, 2014 by Patti*

**science**

Completing Equations of chemical changes: EXample: Al+02- Al2O3 How do Iidentify which type of reaction is taking lace and then balance by using coefficients and not subscripts to balance
*October 3, 2007 by Danny*

**MATH**

im doing solving radical equations how do i do the squareroot of x+1=x+1 the squareroot is only around the first x+1 i got to the part 0=x^2+x is this right and if it is do i factor it or use the quadratic equation. thnx for the help!!!
*March 12, 2008 by gabster*

**math**

My teacher said we are supossed to solve this using systems of equations: Let a, b, and c be real numbers such that a-7b+8c=4 and 8a+4b-c=7. Then a^2-b^2+c^2= ? can someone please help?! i don't know what method to use to solve this or where to start
*September 13, 2009 by chrissy*

**mathhh!**

My teacher said we are supossed to solve this using systems of equations: Let a, b, and c be real numbers such that a-7b+8c=4 and 8a+4b-c=7. Then a^2-b^2+c^2= ? can someone please help?! i don't know what method to use to solve this or where to start
*September 13, 2009 by chrissy*

**math 116**

After solving a system of linear equations, how can you check your answer to determine whether it is correct? Demonstrate the process of checking an answer with an example.
*March 10, 2010 by earl*

**Lynn**

What are some pros and cons of using each of the following methods when solving equations? -graphing -using substitution or elimination I hope to gain additional thoughts on this, thanks.
*June 21, 2010 by Math (Algebra)*

**Calc 2 college**

Modeling with differential equations. If a bacteria culture doubles every 10 minutes and the original culture has 300 cells determine the rate of growth.
*July 9, 2010 by Marianne*

**WORD PROBLEMS WITH EQUATIONS**

Mark has 28 10-cent and 20-cent pieces. How many of each coin does he have if their total value is $4.30? In a class of 26 students, there are four more than girls. How many boys are there?
*May 1, 2011 by Maria*

**physics HELP**

Im having problems getting the magnitude of the force in the problem i asked below i got the frictional and normal force please help me put these equations together
*October 31, 2012 by Anthony*

**Chemistry**

Heat 1kg of CaCO3, get 560g of CaO. Write the reactant equations and solve the mass of CO2 that born. The CaO is 100% pure. Anyone help me, pls?
*August 29, 2013 by Melly*

**Pre-Calc/Trig**

Complete the following for each system that involves one or more quadratic equations: Solve the system algebraically 7y^2-5x^2+20x=3 5x^2+21y^2=209
*January 8, 2015 by Anonymous*

**math**

Sorry I'm posting again-- I just thought it would increase my chances of getting my question answered if i posted it in the mathematics portion of the website also. --------------------------------------- One can of pumpkin pie mix will make a pie of diameter 8 in. If two cans...
*March 8, 2008 by Emily*

**i need help!!!!**

There were 100 more balcony tickets then main-floor tickets sold for a concert. The balcony tickets sold for $4 and the main-floor tickets sold for $12. The total amount of sales for both types of tickets was $3,056. a. write an equations or a system of equations that ...
*June 20, 2005 by casandra*

**MATHEMATICS**

A piece of notebook paper is about 0.0032 inch thick. If you begin with a stack consisting of a single sheet and double the stack 25 times, how tall will the stack be in inches? How tall will it be in feet? (Hint: Write and solve an exponential equation to find the height of ...
*April 8, 2012 by DAN*