Make the x the subject of the formula y= 7x + 4

How do i do this? i don’t understand

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

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?