Hi there!
![\large\boxed{f^{-1}(x) = \sqrt[3]{\frac{x+4}{9} } }](https://tex.z-dn.net/?f=%5Clarge%5Cboxed%7Bf%5E%7B-1%7D%28x%29%20%3D%20%20%5Csqrt%5B3%5D%7B%5Cfrac%7Bx%2B4%7D%7B9%7D%20%7D%20%7D)

Find the inverse by replacing f(x) with y and swapping the x and y variables:

Isolate y by adding 4 to both sides:

Divide both sides by 9:

Take the cube root of both sides:
![y = \sqrt[3]{\frac{x+4}{9} }\\\\f^{-1}(x) = \sqrt[3]{\frac{x+4}{9} }](https://tex.z-dn.net/?f=y%20%3D%20%5Csqrt%5B3%5D%7B%5Cfrac%7Bx%2B4%7D%7B9%7D%20%7D%5C%5C%5C%5Cf%5E%7B-1%7D%28x%29%20%3D%20%5Csqrt%5B3%5D%7B%5Cfrac%7Bx%2B4%7D%7B9%7D%20%7D)
It will take 13 weeks to save the money to buy the equipment because if you subtract 20 you get 55.25 then divide by 4.25 you get 13 <span />
Answer:
5.33
Step-by-step explanation:
5+1/3
=5.3333
=533.33333333%
F(f-1x) will be equal to x
take a simple example
f(x) = 2x
so x = f(x) / 2
f-1(x) = x/2
f(f-1x) = 2 ( x/2) = 2 * x/2 = x