Pleas help me Solve- 8/0.5

What is the inverse of the function f(x) = 2x + 1?

Acomputer store buys a computer system at a cost of $370.80. the selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. answer parts a and b. a. find the current sale price.

Reinel saves 30% of every pay check. his paycheck last week was 560$. how much did reniel save last week?