m = matts age nowm-3 = matts age 3 years ago2m = emilys age now2m-3 = emilys age 3 years ago. It's 3 times larger than matts age was then so: 2m-3 = 3(m-3) = 3m-9 Add 9 and -2m to both sides. 9-3 = 3m - 2m6 = m. Matt is current 6 years old and Emily is currently 12 years old. Three years ago Emily was 9 and Matt was 3. Three times Matt's age then is 9 which is Emily's age 3 years ago!