Question 349994
let son be x years
Zelma = x+18
..
1 year ago
son was x-1 years
Zelma was x+18-1 = x+17 years
..
x+17 = 3(x-1)
x+17 = 3x-3
3x-x =17+3
2x=20
/2
x=10 son's age
Zelma = 10 + 18 = 28 years.