I got this from another question exactly like this one
//////I’m not the one who came up with this answer\\\\\\\ I don’t want to take credit for this))))
From : DeadlyKitty
the key word "times" tells us we are multiplying something
Lisa is 9 years younger than her brother
Paul is 4 times the age of Lisa seven years ago
so now that we have some of this info lets just try to figure this out yeah XD
so we know that she is 9 years younger than her brother right
so lets just say he's 19 and she's 10
10 - 7 = 3
19 - 7 = 12
seven years ago then she was 3 and her brother was 12
SOOOOO
when you divide 12 by 3 you get 4 (4 times older)
when you multiply 3 by 4 you get twelve.
thats where the 4 comes into play
amd technically this question is weird as heck because it doesnt give you numbers to start out with (ages i mean) and so you just woould have to make up some random age.
Hopefully i am not completely wrong :)