Rosa is 14 years older than her sister Amy. 3 years ago, she was 3 times as old as Amy. How old are they now?

Answer 1

R=age of Rosa
A=age of Amy
then form two equations using information given:
"Rosa is 14 years older than her sister Amy." =>
R-A=14 =>
R=A+14.................(1)
"3 years ago, she was 3 times as old as Amy."
Three years ago, both were 3 years younger, so
(R-3)=3*(A-3)
Simplify:
R=3A-9+3 =>
R=3A-6................(2)

Solve for R and A using equations (1) and (2).
Hint: use substitution to solve for R and A.