word problems-quadratic equation
Students sent flowers costing $20 to a sick classmate. There were four fewer students contributing than was planned, requiring each of the others to give 25 cents more. How many students contributed to the gift?

HELP!

Let n be the number that contributed.

Let x be the originally planned contribution

You should get:

n (x + .25) = 20

(n + 4) x = 20

Solve these equations