A Gaelic football team scored 18 times, a mixture of points and goals. A goal is worth three points. If their total score was 28 points, how many goals did they get? (How do you get the answer?)

Respuesta :

x= number of goals
y= number of points

x+y=18

3x+y=28

(3x+y)-(x+y)=28-18

2x=10

x=5
y=13