#include #include "head.h" int main() { int a = 20; int b = 12; printf("a = %d, b = %d\n", a, b); printf("a + b = %d\n", add(a, b)); printf("a - b = %d\n", subtract(a, b)); printf("a * b = %d\n", multiply(a, b)); printf("a / b = %f\n", divide(a, b)); return 0; }