Question

What is the value of the y variable in the solution to the following system of equations?

3x - 6y = 3
7x - 5y = -11

Answer 1

FIrst find the least common multiple of 7 and 3. Which is 21. So, for 3x-6y=3 multiply the equation by 7. For 7x-5y=-11 multiply the equation by 3. Now decide which equation you want to contain -21.

Answer 2

okay so it would be -3

Answer 3

Okay so multiply that equation by 7.

Answer 4

YOu should get -21x + 42y = -21

Answer 5

Then multiply the second equation by 3.

Answer 6

You should get 21x-15y=-33

Answer 7

Now you have
(1) -21x+42y=-21
(2) 21x-15y=-33

Then you can eliminate the 21's. Then combine the y's

Answer 8

So you have 27y=-54 which is y=-2