I need help Write an expression in simplest form that represents the total amount in each situation?

You bought 5 binders that each cost b dollars, a calculator for $45, and a set of pencils for $30.

In 1995 america online had about 3000000 users over the next decade users are expected to increase from a few million to the tens of millions suppose the number of users increased by 150% by the year 2000 how many users will there be in the year 2000