What is wrong with this?

Question

Hello. I am a beginner in C++ language. I don't understand why the code for solving second power equations, runs, but outputs wrong solutions. Thanks in advance.

#include <iostream>
#include <math.h>
using namespace std;

int main()
{
int x1;
int d;
int a;
int b;
int c;
int x2;
int x;
cin >>a >>b >>c;
cout <<"a value " <<a <<endl <<"b value " <<b <<endl <<"c value " <<c <<endl ;
int D = b * b - 4 * a * c ;

// when it has a solution
if (D > 0) {
d= sqrt (D);
x1= ( - b + d) / 2 * a ;
x2 = ( - b - d) / 2* a ;
cout <<"x1 = " <<x1 <<endl <<"x2 = " <<x2 ;
}

// when it has only one solution
if (D=0){
x= -b / 2 * a ;
cout <<" there is only one solution in wich x=" <<x ;
}
//when it doesn't have a solution
if (D<0){
cout << "this equation has no solution";
}
return 0;
}

Answer 1

it should be if (D==0) instead of D=0...

D=0 is not equality operator... it's assignment operator... for comparison, you need to use ==

Answer 2

Use paranthesis for precedence.

I mean write 2*a as (2 * a) and than see the output.

Is it coming true now ?

Answer 3

Also if you have any query regarding code in future please try to post it on playground and paste its link to QnA to get more faster answers to your query.