If f(x)=8(5x-2), find f^-1(x). (A) f^-1(x)=5x+2/8 (B) f^-1(x)=x-16/40 (C) f^-1(x)=5x-2/8 (D) f-1(x)=x+16/40

Answer 1

f(x) = 8(5x-2)

f(x) = 40x - 16

1) Replace f(x) with y:

y = 40x - 16

2) Switch the x and y then solve for y:

x = 40y - 16

x + 16 = 40y

(x+16)/40 = y

3) Change y to f^-1(x):

(x+16)/40 = f^-1(x)