How do you find the slope of a line on a graph

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

An account with a $250 balance accrues 2% annually. if no deposits or withdrawals are made, which graph can be used to determine approximately how many years will it take for the balance to be $282? it's e2020 ni️️as

I’m really confused and need your assist me with this question i’ve never been taught