C #define macros

Question

Here is what i have and I wonder how this works and what it actually does.

#define NUM 5
#define FTIMES(x)(x*5)

int main(void) {
    int j = 1;
    printf(\         


        

Answer 1

Order of operations.

FTIMES(j+5) where j=1 evaluates to:

1+5*5

Which is:

25+1

=26

By making FTIMES((j+5)) you've changed it to:

(1+5)*5

6*5

30