A radical equation is an equation in which a variable is under a radical. To solve a radical equation: Isolate the radical expression involving the variable. If more than one radical expression involves the variable, then isolate one of them.
x represents the total students in the class. We don't know how many teams of four there will be, so we represent that with y. 4y represents the total students in teams of 4. We know there is one team of 5, so that is added to 4y.
