#include <iostream> using namespace std; //вариант 30 int main() { double x1,x2,x3,result; //collecting data cout<<"Input x1,x2 and x3 values:"<<endl; cin>>x1>>x2>>x3; //computing the result result=x1*x2+x1*x3+x2*x3; cout<<"The result is :"<<result<<endl; return 0; }