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)