Question

Please help me in answers 6 and 8

Answer 1

For #6

x + y = -10
x - y = 2

First solve for y in one of the equations

x - y = 2
-y = 2 - x
y = -2 + x
y = x - 2

Now substitute into one of the equations and solve for x

x + y = -10
x + x - 2 = -10
2x - 2 = -10
2x = -8
x = -4