Question

Please help!!!

find the inverse of f(x)=2/3x+6
find f^-1(4)

Answer 1

-3

Explanation:

y = 2/3x +6

Exchange x and y

x = 2/3y +6

Solve for y

x-6 = 2/3y+6-6

x-6 = 2/3 y

Multiply each side by 3/2

3/2(x-6) = 3/2*2/3y

3/2x - 9 = y

The inverse is 3/2x -9

f^-1(x) = 3/2x-9

Let x = 4

f^-1(4) = 3/2(4)-9

= 6-9

= -3