Question

Solve by adding or subtracting. x+y=-10 2x-y=-8

Answer 1

Answer:

$x=-6\\y=-4$

Step-by-step explanation:

To solve, isolate your first equation for y.

$x+y=-10\\y=-x-10$

Now, plug in this y value to your second equation.

$2x-(-x-10)=-8\\2x+x+10=-8\\3x+10=-8\\3x=-18\\x=-6$

Now, plug your x value into your first equation and solve for y.

$-6+y=-10\\y=-4$

Answer 2

Answer:

(-6,-4)

Step-by-step explanation:

I'm going to solve this system by elimination. You can only do this when both equations have the same form; here it is ax+by=c. What that means is a variable gets eliminated after adding or subtracting the equations.

This elimination can be applied to this system by adding the equations. This will elimination the y part because they are opposites.

x+y=-10

2x-y=-8

-‐---------- Adding.

3x+0=-18

3x=-18

Divide both sides by 3:

x=-18/3

x=-6

Using one of the equations we started with along with x=-6, we can find y.

x+y=-10 with x=-6

-6+y=-10

Add 6 on both sides:

y=-4

The solution is (x,y)=(-6 -4).