If x+y=-10 and x-y=2, what is that value of x?

add the equations.

2x=-8
x=-4

X = 8

To find the value of x, you can use the method of solving a system of equations. In this case, we have two equations:

1) x + y = -10
2) x - y = 2

To solve these equations, you can add the two equations together, eliminating the y variable:

(x + y) + (x - y) = -10 + 2
2x = -8

Next, divide both sides of the equation by 2:

2x/2 = -8/2
x = -4

Therefore, the value of x is -4.