so far

//so far
#include <math.h>
#include <cmath>
#if defined(_WIN32) || defined(WIN32) || defined(_CYGWIN_) || defined(_MINGW_) || defined (_BORLANDC_)
#include <iostream>
#define IS_WIN
#else
#include <stdio.h>
#endif

using namespace std;
int main()
{
     double y_one, y_two, x_one, x_two, x, y, c, m;
     cout << "y=mx+c\n";
     cout << "enter y1 + y2\n";
     cout << "y1:\n";
     cin>>y_one;
     cout << "y2:\n";
     cin>>y_two;