#include<iostream>
using namespace std;
int main() {
printf("请输入三个小数\n");
double a = 1.2;
double b= 1.1;
double c = 1.3;
double d = 1.4;
scanf_s(" % f ,%f ,%f", &a,&b,&c);
d = a * 2 + b * 3 + c / (a + 2) - 10;
printf("%f\n",&d);
return 0;
}
空格多了,输出不需要&