What is 7.659 as a expression

Acylinder and its dimensions are shown. which equation can be used to find v, the volume of the cylinder in cubic centimeters?

If a is a nonzero real number then the reciprocal of a is

Ebuka's monthly rent is $750. if ebuka pays the rent late, his landlord charges 4% interest per week that the payment is late. write a function that gives the total cost r(t), in dollars, of ebuka's rent if he pays it t weeks late.