Why is output of this code is 65 and why ain't it is 225?

Question

#include <stdio.h>
#define x 10+5
int main() {
int a=x*x;
printf("%d",a);
return 0;
}

Answer 1

Because #define is just an expression, when the compiler encounters "x" it doesn't calculate the operation, it simply replaces x with 10+5.
So you will have:

int a = 10+5*10+5;
// a = 10+50+5 = 65

If you want the result to be 225 you should write the code like this:

int a = (x)*(x);

Answer 2

Simply it will be calculate ---
10+5*10+5 so answer is 65

Answer 3

Rising Abhinav , because the calculation is the following => 10+5*10+5 => 65. If you place brackets and change the line define x (10 + 5), I think you'll get the desired result.