Respuesta :
The letter r is a placeholder for a value
In this case, you replace r with 9 since r = 9
So we have 24+r turn into 24+9, then we add to get 33
The letter r is a placeholder for a value
In this case, you replace r with 9 since r = 9
So we have 24+r turn into 24+9, then we add to get 33