Question

x+y=-7
2x-y=-8

Answer 1

I'm guessing you want to solve the system.

Answer 2

To do so just add the equations.
\[\huge \left(\begin{matrix} x+y = -7 \\ 2x-y=-8\end{matrix}\right)\]

Answer 3

What do you get?

Answer 4

you would get 2x=-15 i think cuz you cross out either the x or y

Answer 5

i cross out the y

Answer 6

x+y=-7
2x-y=-8
----------
3x - 0 = -15

i though it was supposed to be 3x = -15

also, simplify it by dividing both sides by 3 and you get

x = -5

Answer 7

Correct, you cross out the y
but you forgot to add the x.

you get
as twilight mentioned
3x = -15
from there you divide by 3 to both sides to get your x value of -5.

Answer 8

x + y = -7
-5 + y = -7
y = -2

Answer 9

(-5,-2) is your solution set to your system.