4/23 c++練習三

#include <stdio.h>
#include <stdlib.h>
int main(void)
{
 int x,y;
 int add();
 int minus();
 int multiplication();
 int division();
 x=6;
 y=3;

 printf("(x+y)(x-y)=%d\n",add(x,y));
printf("a*a+a*b*3+b*b=%d\n",formula(x,y));
printf("============================\n");


    system("pause");
    return 0;
}
int add(int a,int b)
{
   return((a+b)*(a-b));
}

int formula(int a,int b)
{
    int result;
    result=pow(a,2)+3*a*b+pow(b,2);  //pow  指數  pow(a,2)  a的2次方
   return(result);
}