Dad has 47 years. son has 13 years. after how many years dad will be tree times older then his son?

4 years.

Step-by-step explanation:

Let the number of years be x, then:

x + 47 = 3(x + 13)

x + 47 = 3x + 39

3x - x = 47-39

2x = 8

x = 4.

d + x = 3(s + x)

47 + x = 3s + 3x

47 + x = 3·13 + 3x

47 - 39 = 3x - x

8 = 2x

x = 4 years

both equations and proportions are better.