Respuesta :

Answer:

24

Step-by-step explanation:

42 + x = 2 (9 +x) (solve for x)

42 + x = 18 + 2x

42 -18 = 2x -x

24 = x

42 + 24 = 66

9 + 24 = 33

When the man turns 66, his son will be 33, or half his age.