Do perpendicular line aways have a slopes that are negative reciprocals?

Which expression is equivalent to7_/x^2 ÷ 5_/y^3? assume y# 0

The interior angles formed by the side of a hexagon have measures of them up to 720° what is the measure of angle a

Hey hotel charges guests $19.75 a day to rent five video games at this rate which expression can be used to determine the charge for renting nine video games for one day at this hotel? pls