In order to use cpctc in a proof, what must you first prove?

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Bill works as a waiter and is keeping track of the tips he ears daily. about how much does bill have to earn in tips on sunday if he wants to average $22 a day? tips by day tips (dollars) monday tuesday wednesday thursday friday saturday $14 $22 $28 $36

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.