Solve using substitution.
y = 8x + 7
y = -8x - 9

Answer:
(-1,-1)
Step-by-step explanation:
1) since both equations are equal to y, we can substitute the value of "y" in one equation to the value of y in another:
8x+7=-8x-9
combine like terms:
8x+8x=-7-9
16x=-16
x=-1
now substitute "x" as -1
8(-1)+7=-1
hence
x=-1
y=-1
so (-1.-1)