Question 344159
NOW:
JOHN=X+3
BILL=X
3 YEARS AGO:
JOHN=(X+3-3)
BILL=(X-3)4
(X+3-3)=4(X-3)
X=4X-12
X-4X=-12
-3X=-12
X=-12/-3
X=4  BILL'S AGE NOW.
4+3=7 JOHN'S AGE NOW.
PROOF:
(4+3-3)=(4-3)4
4=1*4
4=4