# Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this. 2x + 10y = 58 -14x + 8y = 140

91,718 questions, page 31
1. ## Chemistry

Can someone link me videos and sites that can teach me the formula to solve these? Or try to help me understand how to solve these? 1.You have 200g of a radioisotope . If the half-life of this radioisotope is 20 days, how many grams will remain after 40

asked by Samantha on May 16, 2018
2. ## Chemistry - DrBob222 please check and help

Can you check these? And I need help on one. Oxidation Number Method of Balancing Redox Reactions 1)Neutral Solution Sn^2+ + Fe^3+ ----> Fe^2+ + Sn^4+ Balanced equation Sn^2+ + 2Fe^3+ ----> 2Fe^2+ + Sn^4+ 2)Acidic Solution Fe^2+ + Cr2O7^2- ---> Cr^3+ +

asked by Alex on February 21, 2008
3. ## Chemistry - DrBob222 please check and help

Can you check these? And I need help on one. Oxidation Number Method of Balancing Redox Reactions 1)Neutral Solution Sn^2+ + Fe^3+ ----> Fe^2+ + Sn^4+ Balanced equation Sn^2+ + 2Fe^3+ ----> 2Fe^2+ + Sn^4+ 2)Acidic Solution Fe^2+ + Cr2O7^2- ---> Cr^3+ +

asked by Alex on February 21, 2008
4. ## ALGEBRA

2^3+6-5X4=12 show how to solve and show operation

asked by LAMAR on August 31, 2009
5. ## biochem

The pKa of butanoic acid is 4.87. A student mixes 120 mL of 0.45 M butanoic acid with 50 mL of 0.3 M NaOH and adds water to give a final volume of 1 L. What is the pH of the final solution? Please show you work.

asked by Kim on August 31, 2015
6. ## PLEASEEEEEEEEEEEEE HELP. (GEOMETRY)

A right triangle has hypotenuse 8 and area 8. Find the perimeter? I think I have to use Heron's Formula for this question. Please help & show work. Thank you very much. Your work is very much appreciated.

asked by My Name Is Bob on March 27, 2012
7. ## Chemistry

Potentiometric Acid-Base Titration: The tasks to be performed in Experiment #6 include: A. Preparation of a 0.05 M solution of sodium hydroxide (titrant solution). B. Standardization of the titrant solution. C. Calibration of the pH-meter. D. Determination

asked by Malik on October 3, 2014
8. ## Precalculus

Find the discriminant of 3x^2-2x+2=0 and then solve by whichever method seems easiest

asked by Anna bosco on October 6, 2013
9. ## math

use the method of substitution to solve the following pairs of simultaneous equation. 2m+n=0,m+2n=3

asked by joel on January 29, 2017
10. ## Maths

Hi I am new my friend told me to get help here.please can you help me by telling me an easy method to solve this. 9y+2x=

asked by Gerard on August 21, 2017
11. ## math

solve using any appropriate method 10x+y=278 10y+x=107

asked by Keya on August 10, 2014
12. ## mathematical physics

Solve the following ODE using the power series method (1-x^2)y"-2xy'+2y=0

asked by gourav on March 23, 2015
13. ## Math

Solve by Substitution method. 15x-20y=-7 15y=4+5x

asked by Bryan on May 12, 2009
14. ## algebra

use substitution method/linear combinations to solve then tell how many solutions they have -7x+7y=7 and 2x-2y=-18

asked by anna on January 30, 2011
15. ## algebra

also do not understand how to do this. I am not asking for answes, just examples. Solve using the substitution method. 3x – 4y = 5 2x – y = 1

asked by Patte on June 13, 2014
16. ## algebra

solve the set of linear equations by the matrices method: a+3b+2c=3, 2a-b-3c=-8,5a+2b+c=9

asked by linear on April 7, 2015
17. ## chemistry

How to solve CoCl2+HO2- ------> Co(OH)3+ Cl- by half reaction method

asked by Pratik Rathi on July 28, 2016
18. ## Grade 12 AP calculus

You are using Newton's method to solve x3-5x-2=0. If your first guess is x1=2, what value will you calculate for the next approximation x2?

asked by Alannah on December 2, 2012
19. ## math

solve by completing square method 16x^2-24x-13=0

asked by simran on June 28, 2015
20. ## calculus

You are using Newton's method to solve x^3-5x-2=0. If your first guess is X1=2, what value will you calculate for the next approximation X2?

asked by Anonymous on March 2, 2008
21. ## algebra

How would you solve the systemof equations using the substitution method: 2x-9y=2 4x+18y=12

asked by Connor on September 2, 2009
22. ## maths --plse help me..

solve the following equation by method of completing the perfect square:- 4x^2 + 4 √3 x +3=0

asked by Anonymous on December 13, 2012
23. ## Algebra

How do you solve this factoring problem by foil method: 25x2=16

asked by Kate on November 28, 2009
24. ## College Algebra 1

Using the factoring method, solve for the roots of quadratic equation 4x^2=16

asked by James on August 23, 2014
25. ## mathematical physics

Solve the following ODE using the power series method (1-x^2)y"-2xy'+2y = 0

asked by gourav on March 22, 2015
26. ## algebra

Solve by the linear combination method (with or without multiplication). 4g + 5h = 4 8g – 10h = 4

asked by geddy on December 16, 2010
27. ## Finite Math

Solve using Gauss Jordan method - Write in terms of (x, y, z) = ( ) 3y + 2z = 1 2x − y − 3z = 3 2x + 2y − z = 4

asked by Anon on September 17, 2018
28. ## Mathematics

Solve d following que usin substitution method.... 3a=2b+1...equ1 3b=5a-3....equ2

asked by Ogunnaike on January 28, 2016
29. ## MATH

Solve the equation using completing the square method x^2-6x+9 Please I need your solutions

asked by Simon on February 26, 2018
30. ## Math

Solve the pairs of simultaneous equations by the substitution method. 5x-9y=17 3x-8y=5

asked by Gilda on April 19, 2010
31. ## Math

Solve using the annihilator method Y"-8y'+20y=5xe^(4x) sin (2x)

asked by Stephen on November 25, 2014
32. ## College Algebra 1

Using the factoring method, solve for the root: 10x^2-41x=-21

asked by Kenny on August 23, 2014
33. ## math

Solve using the substitution method. Sh 3x + 24y = 24, 27x – 15y = -15 .

asked by carol on May 4, 2011
34. ## math

At the end of Summer, Puss discovers that his radiator antifreeze solution has dropped below the safe level. If the radiator contains 4 gallons of a 25% antifreeze solution, how many gallons of pure antifreeze must he add to bring it up to a desired 50%

asked by Anonymous on March 26, 2016
35. ## Chemistry

1.) It took Beethoven (the composer, not the dog from that movie) 4.5 years to compose the Ninth Symphony (this may not be true, I made it up). How many decades did it take him? 3.) Michael bought a pumpkin that had a mass of 18,165 grams. What was the

asked by Emily on September 21, 2015
36. ## Math (PLEASE HELP!)

1. The UV index on a sunny day can be modelled by the function y= -0.15(x-13)^2+7.6 , where x represents the time of day on a 24-h clock and f(x) represents the UV index. At what time(s) was the UV index 7? 2. Determine if each system has one, two, or no

asked by Adam on June 18, 2015
37. ## maths need help

if a^x=(a/k)^y=k^m and a is not equal to 1 then show that 1/x-1/y=1/m show me work plz

asked by urgent on October 2, 2016
38. ## chemistry, biotechnology

The question is: "The molar extinction coefficient of pure antibody is 1.4 absorbance units per milligram antibody @280nm. You have a concentrated antibody solution, so you make a 5-fold dilution and measure @280, getting an absorbance of 0.845. What is

asked by Jennifer on October 2, 2014
39. ## math

Using these integers:-1,+6,-8,+3,-2 a) Which integers have the greatest product? Show your work. b) Which two integers have the least product? Show your work. Please help I don't understand how to figure this out thank you

asked by Cherie on October 3, 2012
40. ## Solve the polynomial inequality

Solve the polynomial inequality and graph the solution set on a real number line. Express the solution set in interval notation. x^3+x^2+4x+4

asked by Jill on April 9, 2013
41. ## social studies

To which system of government is the federal system most similar? A - The Unitary system B - The confederal system C - The Unitary System D - The confenderal System ******

asked by Blake on March 14, 2016
42. ## Calculus II: Finding the volume of a revolution

Question: Find the volume of revolution bounded by y-axis, y=cos(x), and y=sin(x) about the horizontal axis. Since the rotation is happening at the horizontal axis, I thought the limits of integration would be [-1,1] and if the curves are rotated they

asked by Luna on April 9, 2017
43. ## math

If you know only the outside measurements for any retangle, can you find its area? How? why does this method work?

asked by di on December 14, 2012
44. ## math

Hank Kerchief went to the sale, bought a cd at 30% off and received a \$6.00 discount. What was the original price of the cd??? Show work The \$6 discount WAS the 30% reduction off the original price, P. Solve this equation for P: (1 - 0.30) P = 6

asked by Katelyn on March 27, 2007
45. ## math

Write in terms of cos and sin function. cotx*secx Show work. I know cotx = cosx/sinx and secx = 1/cosx, would that just be the answer or can i solve it?

asked by Need this asap please on April 18, 2016
46. ## 7th grade health please Ms. Sue?

Hi! Sorry, I don't know what subjects you teach, but can you check my answers please? 1. Starches and sugars that provide energy (1 point) kidneys enzymes carbohydrates vitamins 2. The system that removes waste from the body and controls the body's water

asked by Delilah on October 31, 2012
47. ## Algebra 2

write an equation to solve each problem There is only one freshman in the cast of the high school musical. There are 6 sophomore and 11 juniors. One third of the cast are seniors. How may seniors are in the musical? *Please show me the work on how to do it

asked by Dolly on October 15, 2014
48. ## Algebra II

John can clean an attic in 11 hours. DeShawn can clean the same attic in 17 hours. If they worked together how long would it take them? Please solve and show the work. Rounding the answer to the nearest hundredth.

asked by Trista on November 7, 2012
49. ## Algebra I

Write an equation based on the given facts and find the solution. Show all your work, including the steps for solving the equation and checking your answer. –2 times a number plus 12 is –110. Find the number.

asked by Kasey on May 31, 2012
50. ## Geometry

Complete Problem #28 in Section 1.5 Exercises (Chapter 1) of Essentials of Geometry for College Students. Use the table below to show your work and solve the problem. You may add or delete rows as necessary. Statements Reasons PQ=RS Given PS=PQ+RS Segment

asked by Angie on October 4, 2012
51. ## chemistry

A solution is prepared by dissolving 17.1grams of sucrose, c12h22o11, in 275grams of h20. what is the molality of that solution? I know what formula to use, but can someone please show me all the steps to get the answer. Thanks:)

asked by Miley on April 6, 2008
52. ## CHEM

Can you show me the formula I need to do this problem. please a solution is made by dissolving 0.35 mole of LiI in enough water to give a final volume of 2.60 ml. What is the molarity of the solution? thank you

asked by julia on March 25, 2014
53. ## Algebra 1

Hello, could someone help me solve/show the following algebra problem? If there's not enough info given, indicate that no solution can be found. 'Two planes leave chicago - one traveling due east and the other due west. The first travels 100 miles per hour

asked by Charlezetta on June 3, 2010
54. ## Calculus

Suppose that sin q = − 12/13 and that q is a Quadrant IV angle. (a) Find the exact value of cos q. Show work. (b) Find the exact value of sin 2q. Show work.

asked by Brian on March 10, 2012
55. ## precalc

Suppose that cos θ = 12/13 and that θ is a Quadrant IV angle. (a) Find the exact value of sin θ. Show work. (b) Find the exact value of sin 2θ. Show work.

asked by Tony on July 7, 2016
56. ## math

Note: Enter your answer and show all the steps that you use to solve this problem in the space provided. Solve the proportion. 16 50 = x 156 . 25 pls i need help

asked by bird<: on January 28, 2019
57. ## math

I am helping my child with this. Can you show me how to Solve word problems by writing an equation with a variable to represent the given information and then solve the equatin.

asked by prscilla on April 13, 2007
58. ## chemistry

PLEASE SHOW PROCEDURE! You wish to prepare an aqueous solution that has a freezing point of -0.100 degrees Celsius. How many milliliters of 12.0 M HCl would you use to prepare 250.0 mL of such a solution? [Hint: Note that in a dilute aqueous solution,

asked by Cody on July 12, 2012
59. ## prealgebra

Identify the percent of change as an increase or a decrease.Then find the percent of change. #2) Original:23 New:46 and #3) Original:120 New:150 How do you solve this and show your work??

asked by vick on February 27, 2012
60. ## Science Plzz Help

5. How do the circulatory system and the endocrine system interact in helping to maintain homeostasis in humans? A. The endocrine system produces hormones that are transported by the circulatory system to target cells when changes are needed. B. The

asked by Mstv on June 2, 2014
61. ## Math

Solve for x: x^4-15X^2+14=0 How would I solve this problem? Could someone please show me the steps?

asked by Emma on January 10, 2012
62. ## pre-algebra

Nicholas is making cranberry relish for Thanksgiving. The recipe requires five pints of cranberries. Nicolas only has four cups of cranberries. How many more cranberries will Nicholas need to make cranberry relish? Show all your work. Please help don't get

asked by stephanie on November 25, 2012
63. ## Chemistry

Calculate the Ksp of a saturated solution of Mg(OH)2 upon titration with 0.0100 HCl in the presence of phenolphthalein indicator utilizing the data below. mL saturated Mg(OH)2 titrated - 1382 mL of 0.0100 M HCl to endpoint - 38.7 Please help me and show

asked by Amy on March 19, 2019
64. ## computer science 104

Create a method areaOfaTrapeziod when given a, b, and h (all doubles), will return the area (double) of a trapezoid. Use the equation pictured below In the code, i should 1. Create the prototype for the method 2. create the method 3. call it from the

asked by Nan on November 3, 2011
65. ## Chemistry;

for a solution of the weak base, 0.075 M ethylamine C2H5NH2(aq), the hydroxide ion concentration (OH-) is 6.6x10^-3 M. Assume that temperature is constant and volumes are additive. a. Write the equilibrium dissociation equation. b. What's the pH of 0.075 M

asked by Sharon on January 27, 2011
66. ## Physics

A 14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. Find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earth’s velocity. Earth’s mass is 6.0 × 1024 kg. Show

asked by Pat on January 27, 2012
67. ## Science

How do the circulatory system and the endocrine system interact in helping to maintain homeostasis in humans? A. The endocrine system produces hormones that are transported by the circulatory system to target cells when changes are needed. B. The

asked by Anonymous on November 17, 2015
68. ## Biochemistry

You wish to make 3 reactions (1 ml each) with the specified amounts of protein. The remainder of each reaction consists entirely of buffer. The source of your protein is a stock solution that has a concentration of 0.5 mg/ml. What is the volume of stock

asked by Alwxy on October 22, 2016
69. ## math

1-AND PRODUCTION sum of roots of the equation :X²-X-6=0 2-FOR what values of A the equation has no solution ax ² +3 x-7 = 0 3-For what values of x the equation has 2 solution X²-X+C=0 4-Solve the equation (X-1)²-4=0 5-Solve the equation a)2/2

asked by Anonymous on September 26, 2010
70. ## Chemistry. Please help

How many milliliters of glacial acetic acid (17.3 M) would you need to titrate an aqueous solution of 100 grams sodium acetate (MW = 82.0 g mol-1) to get a final pH of 5.00 and a final volume of 1.00 liter? The pK’ for acetic acid is 4.76. Show your

asked by Trey on September 10, 2012
71. ## Chemistry really desperate

How many milliliters of glacial acetic acid (17.3 M) would you need to titrate an aqueous solution of 100 grams sodium acetate (MW = 82.0 g mol-1) to get a final pH of 5.00 and a final volume of 1.00 liter? The pK’ for acetic acid is 4.76. Show your

asked by Trey on September 10, 2012
72. ## finance

13. A project has the following cash flows. What is the internal rate of return? Year 0 cash flow -\$443,600 1 \$224,800 2 \$224,800 3 \$ 67,200 (Please calculate the solution and show your work)

asked by Vanessa on January 2, 2012
73. ## Desperate chemistry

How many milliliters of glacial acetic acid (17.3 M) would you need to titrate an aqueous solution of 100 grams sodium acetate (MW = 82.0 g mol-1) to get a final pH of 5.00 and a final volume of 1.00 liter? The pK’ for acetic acid is 4.76. Show your

asked by Trey on September 10, 2012
74. ## Chemistry

How many milliliters of glacial acetic acid (17.3 M) would you need to titrate an aqueous solution of 100 grams sodium acetate (MW = 82.0 g mol-1) to get a final pH of 5.00 and a final volume of 1.00 liter? The pK’ for acetic acid is 4.76. Show your

asked by Trey on September 10, 2012
75. ## Algebra

A train leaves Danville Junction and travels north at a speed of 75 km/h. Two hours later, a second train leaves on a parallel track and travels north at 125 km/h. How far from the station will they meet? I have no idea what the system of equations would

asked by Willow on February 23, 2009
76. ## math

Solve each equation , then write the general solution cos(pi/2(x+1))=cospi/2 x x=1.5, 3.5 general solution: 1/2+4n but the back of the book says that the general solution is 1/2+2n isn't the period 4?

asked by sh on February 6, 2009
77. ## science

How much work is done on a 30 N rock that is lifted 1.5 m off the ground? show work.

asked by jenna on January 4, 2011
78. ## math

what is 120% of 40? show work or tell how you did it I laid out the others, you try this one, and I will critique your work.

asked by alexllly on April 25, 2007
79. ## Chemistry

How do the following solutions show the properties of a buffer? 1) 50 ml 0.10 M NH3 + 50 ml 0.10 M NH4NO3 2) 10 ml solution #1 + 5 ml H2O + 1 ml 0.10 M HCl 3) 10 ml solution #1 + 6 ml 0.10 M HCl 4) 10 ml solution #1 + 5 ml H2O + 1 ml 0.10 M NaOH

asked by Jeremy on March 20, 2013
80. ## Chemistry

When 23.3 mL of 0.14 M HCl are added to 50.0 mL of a 0.16 M solution of a weak monoprotic base, the pH of the solution is 10.50. What is the Kb of the weak base? do u find moles of both and then add the moles for HB+ and then just use the B- moles for the

asked by Chris on March 8, 2009
81. ## Math gr 12

Help! My friend let me borrow their notes and I don't know how they got these answers because they didn't show their work. Could someone please help me? *The answers are correct btw. David is flying from Detroit to Las Vegas. The airfare is \$476. He can

asked by Anon on December 4, 2017
82. ## chemistry-Dr Bob

is that a -56? Dr. BOb. thank you When 27.20mL of .5 M H2SO4 is added to 27.20 of 1M KOH in a coffee cup calorimeter at 23.5 degrees C, the temp rises to 30.17 degrees C. Calculate delta H of this reaction. (Assume that the total volume is the sum of the

asked by patrick on October 18, 2015
83. ## chemistry

is that a -56? Dr. BOb. thank you When 27.20mL of .5 M H2SO4 is added to 27.20 of 1M KOH in a coffee cup calorimeter at 23.5 degrees C, the temp rises to 30.17 degrees C. Calculate delta H of this reaction. (Assume that the total volume is the sum of the

asked by patrick on October 17, 2015
84. ## Algebra

Solve y= 2x+ 3 and y= 4x+3 I came up with the answers (0,3) using both substitution and elimination methods. What is the "independent" variable and "dependent" variable? What would be a "real world situation" including independent and independent

asked by J. J. on May 15, 2016
85. ## please check my answer

please check my answer thanks :) You are the manager of The Candle Shop using the FIFO method of inventory pricing, what is the dollar value of the ending inventory if there were 17,000 units on hand Dec 31 Show all of your work Jan 1 5,000 @ \$0.89 Feb15

asked by keleb on January 7, 2008
86. ## Indices

P=(64)^-2 Q=1/16^(1/3) R=8root2 Express pqr as a power of 4 P=4^(-6) Q=4^(-2/3) R= ???????? How can i find R? *please show me the method for future reference* Thankyou

asked by Anonymous on September 29, 2015
87. ## math

Solve. Please show all of your work. Find the length and width of a rectangular lot with a perimeter of 108 meters if the length is 8 meters more than the width.

asked by christine on August 15, 2011
88. ## Algebra

Solve the system 9x-5y=119 18x-10y=238 Double both sides of the first equation and you have 18x-10y =238 which is the same as the second equation. Since the two equations are not independent, there are no unique solutions. Thee are an infinite number of

asked by Tabby on December 14, 2006
89. ## algebra

use substitution to solve the linear system 3x-y=15 x+2y=-2 Solve for y in one formula, and then substitute that value for y in the other formula to solve for x. Once you find x, substitute that value into either formula to get the value for y. 2y = -2 - x

asked by lisa on March 7, 2007
90. ## Chem

In procedure B2, you will titrate a saturated solution to find out how much of the anion dissolved. Assume you we're able to dissolve about 0.12g of potassium hydrogen tartrate in 25.0 mL of water. For the titration, you will use 10.00mL of this sample.

asked by K on March 8, 2013
91. ## statistics

The population standard deviation (σ) for a standardized achievement test that is normally distributed is 8.    a.) Calculate the standard error of the mean if you draw a random sample of 50 test scores.  Show your work for full credit .  .  .  b.)

asked by PK on February 21, 2012
92. ## largest possible area

Again from applications of derivatives.. what is the largest possible area for a right triangle whose hypotneus is 5cm long, and what are its dimensions. Thanks a^2 + b^2 = c^2 3^2 + 4^2 = 5^2 Area of a triangle 1/2 base times altitude hint: base is 3

asked by Jen on November 18, 2006
93. ## chemistry

Calculate the pH of the buffer system after the addition of 0.1 mol of gaseous HCl of the solution. Assume that the volume of the solution does not change when the HCl is added.

asked by zayde on March 30, 2015
94. ## calculas

caluclas (intersection of three planes) HELP!!!? in the equations k is a real number 1.x-2y+z=4 2.x-y-z=3 3.x+y+kz=1 for what values of k does the system 1.have exactly one solution? 2.have an in finite number of solution?

asked by ram on March 27, 2011
95. ## Calculus I

Using Newton's Method, determine the first approximation to the solution of: e^(4x)= 10-2x starting with x=0 what is x1= ??? P.S. ( the 1 is a subscript )

asked by Matthew on April 8, 2011
96. ## Math

Use the substitution method to find solution sets (x,y) for the following systems of equations: 3x-5y=-11 6x+2y=26

asked by Scott on June 20, 2009
97. ## Physics

Can someone walk me through how to work this? It's worded weirdly and I'm not sure how to solve it. Mass M1= 2.2 kg lies on a frictionless table, pulled by another mass M2= 4.1 kg under the in of Earth's gravity. a) What is in N the net force acting on the

asked by James on March 3, 2015
98. ## grasping algebra concepts

My book is showing the solution for graphing a system of linear equations y > 2x - 7 y is greater than or equal to -3x + 7 I see the way they graphed it and both lines intersect at one point. Did the just find -7 and +7 on the line in order to graph or did

asked by Shawn on August 22, 2007
99. ## chemistry step by step for me. Thank a lot

342gm of 20% by mass of ba(oh)2 solution sq gr .57 is reacted with 1200ml of 2m hn03. if the find density is same as pure water then molarity of the ion in resulting solution by nature of the above solution is dentified. The answer 0.888M Who helps me to

asked by Ken on July 19, 2014
100. ## ap calc

An oil well at O is in the ocean, 8 miles from T on a straight shoreline. The oil has to go from O to R. the cost of laying pipe per mile is \$90,000 underwater and \$54,000 on land. the cheapest method of placing the pipe is to lay OP underwater and PR on

asked by Anonymous on November 18, 2014