Question 245479
girl=g 
father=f
g=f/4
g+7=(f-12)/2
f/4+7=(f-12)/2
multiply both sides by 4
f+28=2f-24
subtract f from both sides
28=f-24
52=f
13=g
check
13=52/4
13=13

13+7=(52-12)/2
20=40/2
20=20