isabel is represented as x
ruth is represented as x+2
so the equation would be
x+(x+2)=22
the (x+2) is ruth. so to check if its right solve it. 2x+2=22
-2 -2
2x+20
__ ___
2 2
x=10
so now you know that isabel scored 10 goals since she was x. to figure out ruth just add 2.