Help please :( 4^5 x 4^ -7 divide by 4^ -2 ?

How can you decide witch operations to use to slice a two step equation

Astore has clearance items that have been marked down by 60%. they are having a sale, advertising an additional 55% off clearance items. what percent of the original price do you end up paying?

Maurice has 54 fewer comic books than rebecca.they have 130 comic books together .how many comic books are in maurices collection ? how many comic books are in rebeccas collection