Question 132308
LET THE GIRL'S AGE = X & HER FATHER'S AGE = 4X WHICH IS THERE AGES NOW.
IN 7 YEARS THE GIRL'S AGE WILL BE (X+7).
IN 7 YEARS THE FATHER'S AGE WILL BE(4X+7).
(X+7)=(4X-12)/2
X+7=(4X-12)/2 NOW CROSS MULTIPLY
2(X+7=4X-12
2X+14=4X-12
2X-4X=-12-14
-2X=-26
X=-26/-2
X=13 YEARS OLD FOR THE GIRL NOW.
4*13=52N  AGE OF THE DAD NOW.
PROOF
13+7=(4*13-12)/2
20=(52-12)/2
20=40/2
20=20