the ratio of father's age to his son age is 8:3. in 5 year's time the sum of their ages will be 54. how old are they

Answer 1

let their ages be 8x and 3x

in 5 years:
father's age = 8x+5
son's age is 3x+5

8x+5 + 3x+5 = 54

solve for x, plug into my definitions

Answer 2

8xplus 5 plus 3x plus 5 is equal to 54
11x plus 10 is equal to 54
11x is equal to 54-10
11x is equal to 44
Divide by 11 both side
X is equal to 4