How the answer is 9 for this code?

Question

#include <stdio.h>
#define square(x) x * x

int main() {
printf("%d", square(4+1));
return 0;
}

Answer 1

Square (x) is x * x
So if we pass 4+1 as x
This is how things happens here
S1: 4+1*4+1
S2: as the * has high precedence than + from left to right 1*4 = 4
S3: 4+4+1 = 9

Precedence matters a lot

If u use square (x) (x)*(x), you'll get 25 as answer
Because (4+1)*(4+1) -> 5*5 = 25

Hope you understand.