Question

What is the value of the x variable in the solution to the following system of equations?
2x + 2y = 6
x + 3y = −1

a. -2
b. 2
c. 5
d. -5

Answer 1

I like using elimination method.
Multiply the second equation by 2:
2(x+3y)=2(-1)
2x+6y=-2
Then subtract the second equation from the first.
(2x+2y=6)-(2x+6y=-2)
That eliminates the 2x to get -4y=8
y=-2
To get x, plug in y=-2 in the first or second equations. I choose the second.
x + 3y = −1
x=-1-3y
x=-1-3(-2)
x=-1+6
x=5