Question

If f(x) = 7x – 12, what is f–1(x) ?

Answer 1

y = 7x - 12

Answer 2

solve for y:
y + 12 = 7x
x = (y+12)/7

Answer 3

so now just swap x and y:
y = (x+12)/7

Answer 4

so f-1(x) = (x+12)/7

Answer 5

F(x)=7x-12
Y=7x-12
X+12=7y
x+12/7=y
y+12/7=x=f-1(x)