Question

The sum of two numbers is 28. The first number, x, is three times the second number, y. Which system of equations can be used to find the two numbers?

Answer 1

The ratio is 1:3.

The second number,y, is 7 and the first number, x, is 21.

Answer 2

First x+y=28 (1)
Second x=3y


(1) => 3y+y=28 => 4y=28 => y=7 and x=3y =3*7=21