Why the output of this code is 9?

Question

https://code.sololearn.com/cFliu1dBcK7f/?ref=app

Answer 1

try the following
#define square(x) (x)*(x)

C literally substitutes text
so right now it says
4+1*4+1 = 9

Answer 2

https://code.sololearn.com/cZlQt6ekvT94/?ref=app

just put one more bracket