math
posted by cely on .
Tanya is 12 years older than leah. Three years ago, Tanya was five times as old as leah. How old is leah?

let Leah present age be x yrs
then Tanya is now x+12
Three years ago, Leah was x3
and Tanya was x+12  3 or x+9
at that time "Tanya was five times as old as leah"
x+9 = 3(x3)
x+9 = 3x  9
18 = 2x
x = 9
So Leah is now 9, and Tanya is now 21
check:
three years ago Leah was 6 and Tanya was 18
Was Tanya three times as old?
is 18 equal to 3 times 6? 
Tanya's age t is three times Martin's age m.