The surface area of a sphere is S(x) = 4πx2, where x is the length of the radius of the sphere. Restrict the domain to create a one-to-one function. Find and describe the inverse function

Apublic library wants to place 4 magazines and 9 books on each display shelf. the expressions 4s +9s represents the total number of items that will be displayed on s shelves. simplify this expression

If f(x)= 3x+6 which of the following is the inverse of f(x)

Can someone me do math because i am having a breakdown rn because i don’t get it