How do you solve the system of equations y=-x-4 and y=x+2?

2 Answers
Mar 20, 2018

x = -3 and y = -1.

Explanation:

y = -x-4
y = x + 2
Substituting -x-4 for y:
-x-4=x+2
2x = -6
x=-6/2
x=-3
Substituting -3 for x to find y:
y = 3 -4
y=-1

Mar 20, 2018

x = -3
y = -1

Explanation:

Since both equations are set in terms of y (y equals), we can set both equations equal to each other:

-x-4=x+2

From here we can solve a very simple equation:

-x-x=-2x (Get like terms on both sides, x's on the left, coefficients on the right)
4+2=6
-2x=6
x=-3

Now that we have x, we can choose one of either equations to solve for y, and plug both values in after to double check:

y=-(-3)-4
y=3-4
y=-1

Let's double check by using the other equation:

y=x+2
(-1)=(-3)+2
-1=-1,
True