x+9y=-42 3x+8y=-50 solve using the substitution method.

x+9y=-42

3x+8y=-50

x = -42 - 9y

3(-42 - 9y) + 8y = -50
-126 - 27y + 8y = -50
-19y = 76
y = -4

Can you take it from here?