First you need to set up a formula. Underline all of your givens:
Spent 1/2 on clothes
$6 more for washing windows
Ended with $10.
now you need to set up an equation.
You know she ended up with $10. So that will be what it equals. Then you know that she earned $6 in addition to her allowance. So this would be (x= allowance) (x+6)/2 = 10.
Now you need to solve for x.
Multiply both sides by 2.
x+6=20
Now subtract both sides by 6 to get x alone:
x=$14
