Afootball team begins the season with 25 players . each month they get 3 more players . write an equation i represent the relationship between the numbers of months the football team has been playing ,x, and the total number of players ,y

You want to find y so it should start with y=
then the next piece that is unknown is the number of months, but you know there are 3 new ones each month so you know you have to have 3x so you have y=3x
and then you can't forget to keep the original 25 on the team so y=3x+25