#include<bits/stdc++.h> using namespace std; int main() { double x,y,a; cin>>x>>y; a=(87x+85y)/(x+y); cout<<fixed<<setprecision(2)<<a<<endl; return 0; }

#include<bits/stdc++.h> using namespace std; int main () { double x,y; cin>>x>>y; cout<<fixed<<setprecision(2)<<(x87+y85)/(x+y); return 0; }

思路

根据平均分计算公式可知，答案为：

$$(x \times 87.0+y \times 85.0)/(x+y)$$

code

#include<bits/stdc++.h>
using namespace std;
int main(){
   int x,y;
   cin>>x>>y;
   printf("%.2lf",(x*87.0+y*85.0)/(x+y));
   return 0;
}

#include<bits/stdc++.h>
 using namespace std; 
double x,y;
int main() 
{ cin>>x>>y;
 cout<<fixed<<setprecision(2)<<(87.00*x+85.00*y)/(x+y);
 return 0; 
}

#include<bits/stdc++.h> using namespace std; double x,y; int main() { cin>>x>>y; cout<<fixed<<setprecision(2)<<(87x+85y)/(x+y); return 0; }