Answer:
(a-4)x-b+9
Step-by-step explanation:
hope this helps
f^-1 (x) = - 6x-1 / 10 + 9x
x = 6
y = -6
x + y = 0 (Multiply by -1)
x + 9y= -48
-x - y = 0
8y = -48
x + y = 0
x - 6 = 0