Respuesta :

Answer: y - 9

Step-by-step explanation:

Because "y" will be John's age in 5 years, we subtract 5 to get to his age now.

y-5

Four years ago will be just subtracting 4.

y-9

y - 9 (to get the at which he is now, substract 5 from y, and then substract 4, as we need to know what age he was 4 years before now)