Please help me out with this, AND NO LINKS PLEASE

In simplified exponential notation, the expression a^2•a^-3•a 1/a 0

Fanny mendelssohn manages all the magazines and paperback books at a local grocery store. she prices many paperbacks to sell at $7.99. the cost to the store is $5.29. what is the markup rate on a paperback book, based on its cost?

The functions below show the amount of money bella and sweet t had saved after earning money for doing chores. which description best compares the two functions?