25% of what is 84? help me and my other questions, please.

The marriott family bought a new apartment three years ago for $65,000. the apartment is now worth $86,515. assuming a steady rate of growth, what was the yearly rate of appreciation? what is the percent of the yearly rate of appreciation?

Ineed to know the answer to this algebra question.

What function has a range {yly< 5}? question on picture above^