# simultaneous equations

Solve
2a + b = 3
4a - 5b = 20

My attempt
Multiply the first equation by 5
So,
10a + 5b = 15
4a - 5b = 20
14a = 35
Divide both sides by 14
a = 2.5
Substitute (I have done it with the second one)
10 - 5b = 20
Take away 10 from both sides
5b = 10
Divide both sides by 5
b = 2

When I checked if the answers were right by fitting them back into the equation it didn't work

1. 👍 0
2. 👎 0
3. 👁 122
1. b = NEGATIVE TWO
scroll down to your first question for my solution

1. 👍 0
2. 👎 0
posted by Damon

## Similar Questions

1. ### algebra

Solve. x/9-1/7=26/63 STEP 1: The LCM is _________ To clear denominators, multiply each side of the equation by the LCM. _______/1 (x/9-1/7)=__________/1 multiply 26/63. STEP 2: Use the Distributive Property. _____/1 multiply x/9 -

asked by sally on March 1, 2013
2. ### math

Multiply and simplify 2/3*13 The answer is 22. Right? if you mean (2/3) * 13 or 2 / (3*13) i believe according to both your answer is wrong Is that (2/3)*13? If so, then (2*13)/3= something other than 22. Or if it is 2/(3*13) = it

asked by KC on August 19, 2007
3. ### Math

The problem to solve is: (x+20)(x-12)(x+4)>0 but I can't figure out how to do this right so I left off the >0 and tried to solve the equation. x+20 evaluates to x+20 x-12 evaluates to x-12 Multiplying x+20 by x-12 is a classic

asked by Sabrina on September 24, 2010

.50 - x / x = 3.20e-1 I need to solve for x. I was going to do .50 X 3.20e-1 and then take the square root but this is not correct. I am not sure what to do. Thank you for your help. Math(Please help) - Reiny, Tuesday, April 17,

asked by Hannah on April 18, 2012
5. ### simultaneous equations

Solve 2a + b = 3 4a - 5b = 20 My attempt Multiply the first equation by 5 So, 10a + 5b = 15 4a - 5b = 20 Add them together 14a = 35 Divide both sides by 14 a = 2.5 Substitute (I have done it with the second one) 10 - 5b = 20 Take

asked by hs on January 10, 2014
6. ### applied calculus

3. a) Write out the limit definition for the derivative of y = xx. Attempt to solve it. b) Write out the limit definition for the derivative of the inverse trig function from question 2. Attempt to solve it. c) Discuss the value

asked by jack on April 9, 2013
7. ### Applied calculas

3. a) Write out the limit definition for the derivative of y = xx. Attempt to solve it. b) Write out the limit definition for the derivative of the inverse trig function from question 2. Attempt to solve it. c) Discuss the value

asked by jack on April 8, 2013
8. ### Math

A student is trying to solve the set of two equations given below: Equation A: x + z = 6 Equation B: 2x + 4z = 1 Which of the following is a possible step used in eliminating the z-term? Multiply equation B by 4. Multiply equation

asked by Nikki on May 4, 2017
9. ### math

Jen, I will attempt to write the others out. #3)ADD: -57 + (-22) I got -79 #4)Subtract -2.3-(-8.8) I got -6.5 #7)perform indicated operation: -21 - (-9) I tried to underline ----------- -21 - (-21) I got -12 over o or undfined

asked by barbara on July 18, 2010
10. ### Math

8*2sq+7*(4+1)= ? Can someone explain to me what to after the parenthesis? I mean in the PEMDAS of operations says that I should multiply. Multiply what and when? By the way the actual problem is a example I got out of my book.

asked by Rindi on August 11, 2007

More Similar Questions