f(x) = 7x + 5 g(x) = x + 1
f (g(x) ) = f( x + 1 ) = 7(x + 1) + 5 = 7x + 7 + 5 = 7x + 12
h(x) = 7x + 12
Substituting 'y' for 'h(x)' [making it easier to write]
y = 7x + 12
Finding the inverse:
x = 7y + 12 ---> x - 12 = 7y ---> y = (x - 12) / 7
f-1(x) = (x - 12) / 7
