2-5

#include<stdio.h>
in/* 计算二分段函数 */
t main(void)
{
    double x,y;


    printf("Enter x (x>=0:\n"); 


    scanf("%lf",&x);
    /*if-else 语句 */
    if(x<=15){
        y=4*x/3
    }
    else{
        y=2.5*x-10.5;
    }
    printf("y=f(%f)=%.2f\n",x,y);/*


  return 0;
}