
Example: Mike is 7 years younger than Jill. Together, there ages add up to 19. Find both their ages. Solution: Let x = Jill's age Then x  7 = Mike's age Their ages add up to 19 x + (x7) = 19 x + x  7 = 19 2x  7 = 19 2x  7 + 7 = 19 + 7 2x = 26 x = 13 x  7 = 13  7 = 6 Verification: x + (x7) = 13 + (137) = 13 + 6 = 19 Jill is 13 and Mike is 6 year old. Example: Harold's age is four times the sum of the ages of his two daughters. Six years hence, his age will be double the sum of their ages. Find Harold's age. Solution: Let the sum of the ages of his two daughter be 'x' years. Harold's age = 4x Six years hence, the sum of the ages of the two daughters = x + 6 + 6 = x + 12 Harold's age = 4x + 6 4x + 6 = 2(x + 12) 4x + 6 = 2x + 24 2x = 24  6 = 18 x = 9. Harold's age = 4x = 36 years Directions: Solve the following word problems. 