Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func gcd(num1, num2 int) int {
	if num2 == 0 {
		return num1
	}
	num3 := num1 % num2
	return gcd(num2, num3)
}

func lcm(num1, num2 int) int {
	if num1%num2 != 0 {
		num3 := gcd(num1, num2)
		for i := 1; ; i++ {
			check := num3 * i
			if check%num1 == 0 && check%num2 == 0 {
				return check
			}
		}
	} else {
		return num1
	}
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		strNums := strings.Fields(scanner.Text())
		nums := []int{}
		for _, strNum := range strNums {
			num, _ := strconv.Atoi(strNum)
			nums = append(nums, num)
		}
		a := nums[0]
		b := nums[1]
		c := nums[2]
		d := nums[3]
		e := nums[4]
		f := nums[5]
		lcm := lcm(a, d)
		mulA := lcm / a
		mulD := lcm / d
		a *= mulA
		b *= mulA
		c *= mulA
		d *= mulD
		e *= mulD
		f *= mulD

		if d < 0 {
			d *= -1
			e *= -1
			f *= -1
		}

		bE := b - e
		cF := c - f
		y := float64(cF) / float64(bE)
		x := (float64(c) - (y * float64(b))) / float64(a)

		if x == 0 {
			fmt.Printf("%.3f ", 0.0)
		} else {
			fmt.Printf("%.3f ", x)
		}
		if y == 0 {
			fmt.Printf("%.3f\n", 0.0)
		} else {
			fmt.Printf("%.3f\n", y)
		}
	}
}

C++: #include <iostream>
#include <iomanip>
int main()
{
  int a, b, c, d, e, f;
  while (std::cin >> a >> b >> c >> d >> e >> f) {
    double x, y, r;
    r = static_cast<double>(a * e - b * d);
    x = static_cast<double>(c * e - b * f) / r;
    y = static_cast<double>(a * f - c * d) / r;
    std::cout << std::fixed << std::setprecision(3) << x << " " << y << std::endl;
  }
  return 0;
}

C++: #include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <list>
#include <vector>
using namespace std;

int main(int argc, char const *argv[]) {
  double x, y;
  double a, b, c, d, e, f;
  while (!(cin >> a >> b >> c >> d >> e >> f).eof()) {
    x = (e * c - b * f) / (a * e - b * d);
    y = (a * f - c * d) / (a * e - b * d);
    std::cout << fixed << setprecision(3) << x << " " << y << '\n';
  }
  return 0;
}

C++: #include<cstdio>
#include<iostream>
using namespace std;
int main(){

  double a,b,c,d,e,f;
  double x,y;

  while(cin >> a){
    cin >> b >> c >> d >> e >> f;
    
    if((a*e-d*b) == 0) x = 0;
    else x = (c*e-f*b)/(a*e-d*b);
    if((b*d-e*a) == 0) y = 0;
    else y = (c*d-f*a)/(b*d-e*a);

    printf("%.3lf %.3lf\n",x,y);
  }
  return (0);
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cmath>
#include <iomanip>
 
using namespace std;

static int N = 2;
int pivot;


int main(){
    int i, j, k, n;
  
    // ?????§?????°?????? M
    double M[N][N + 1];
    for (int i = 0; i < N; ++i){
        for(int j= 0; j < N+1; ++j){
            cin >> M[i][j];
        }
    }
    
  

 
    double pivot, mul;
 
    // ????§??????????1??§??£????????????????????????????????????(???????¶????)
    for (i = 0; i < N; ++i){
        // ????§??????????????????????????????§??????????????£??????
        pivot = M[i][i];
        for (j = 0; j < N + 1; ++j){
           M[i][j] = (1 / pivot) * M[i][j];
        }
 
    // ???????????????????????????????????¨?????????????????????????????????
    // i??????????????????0???????????????????????¬?????¢?????????
         for (k = i + 1; k < N; ++k){
            mul = M[k][i];
            for (n = i; n < N + 1; ++n){
                M[k][n] = M[k][n] -  mul * M[i][n];
            }
        }
    }
 
    // ???????????????????????£????????°?????£??\???????????¬??????????§£?????¢?????????(????????£??\)
    // ????????¨??????????????????????????§?????¬??????????§£???????????????
    for (i = N - 1; i > 0; --i){
        for (k = i - 1; k >= 0; --k){
            mul = M[k][i];
            for (n = i; n < N + 1; ++n){    
                M[k][n] = M[k][n] - mul * M[i][n];
            }
        }
    }
    cout << fixed << setprecision(3) << M[0][2] << " " << M[1][2] << endl; 
}

C++: #include <iostream>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <algorithm>
#include <stdlib.h>

using namespace std;
double a, b, c, d, e, f;
double x, y;


void function(){
	if(c/b == f/e){
		x = 0;
		y = c/b;
	}else if(c/a == f/d){
		y = 0;
		x = c/a;
	}else{
		y = (c*d - a*f)/(d*b - a*e);
		x = (c - b*y)/a;
	}
	return;
}


int main(){
	int n;
	cin >> n;

	for(int i=0 ; i<n ; i++){
		double x1, y1, x2, y2, x3, y3;
		cin >> x1 >> y1 >> x2 >> y2 >> x3 >> y3;

		a = 2*(x2 - x1);
		b = 2*(y2 - y1);
		c = (x2 - x1)*(x1 + x2) + (y2 - y1)*(y1 + y2);

		d = 2*(x3 - x1);
		e = 2*(y3 - y1);
		f = (x3 - x1)*(x3 + x1) + (y3 - y1)*(y1 + y3);

		function();
		double r;
		r = sqrt((x - x1)*(x - x1) + (y - y1)*(y - y1));

		printf("%.3lf %.3lf %.3lf\n",x, y, r);
	}
	return 0;
}

C++: #include<stdio.h>

int main(void){
	int i,j,k;	//sñ\¦
	double p,d,a[5][5]={0};			//p=s|bgAd=XC[vìÏ
	
	
	while(scanf("%lf %lf %lf %lf %lf %lf",&a[0][0],&a[0][1],&a[0][2],&a[1][0],&a[1][1],&a[1][2])!=EOF)
	{		
	
		//printf("%fx+%fy=%f\n",a[0][0],a[0][1],a[0][2]);		mF
		//printf("%fx+%fy=%f\n",a[1][0],a[1][1],a[1][2]);
	
	
		for(k=0;k<2;k++){
			/* s{bgXC[vìÅWðÎp»:s{bgW */
			p=a[k][k];	
			
			for(j=k;j<(2+1);j++){
				/* s{bgsÌeWðs{bgWÅé*/
				a[k][j]=a[k][j]/p;
			}
			
			for(i=0;i<2;i++){
				/*s{bgñÌXC[vì:s{bgsÅÈ¢êÌÝÀs */
				if (i!=k) {   
					d=a[i][k];
					
					for (j=k;j<2+1;j++){
						a[i][j]= a[i][j]-d*a[k][j];
					}
				
				}
			}
		}	
	
		
		for (k = 0; k < 2; k++){
			printf("%.3f ",a[k][2]);
		}
		
		printf("\n");
	}	
	
	return 0;
}

C++: #include<iostream>
#include<iomanip>

int main(){
        int a,b,c,d,e,f;
        while(std::cin >> a >> b >> c >> d >> e >> f){
                double x, y;
                int p,q;
                p = a * e - d * b;
                q = c * e - f * b;
                x = q / p;
                y = (c - a * x) / b;
                std::cout << std::fixed << std::setprecision(3) << x << " " << std::setprecision(3) << y << std::endl;
        }
        return 0;
}

C++: #include<iostream>
#include<iomanip>
using namespace std;

int main()
{
  double a[10],b[10];
  for(int i=0;i<6;i++)
  {

	  cin>>a[i];
	  if((a[i]>1000)||(a[i]<-1000)){
	    cout << "nomber error" <<endl;
	    return 0;
     }
  }
  for(int i=0;i<6;i++)
  {

	  cin>>b[i];
	  if((b[i]>1000)||(b[i]<-1000)){
	    cout << "nomber error" <<endl;
	    return 0;
     }
  }
  cout<<setprecision(4)<<(a[2]*a[4]-a[1]*a[5])/(a[0]*a[4]-a[1]*a[3])<<" ";
  cout<<setprecision(4)<<(a[2]*a[3]-a[0]*a[5])/(a[1]*a[3]-a[0]*a[4])<<" ";
  cout<<setprecision(4)<<(b[2]*b[4]-b[1]*b[5])/(b[0]*b[4]-b[1]*b[3])<<" ";
  cout<<setprecision(4)<<(b[2]*b[3]-b[0]*b[5])/(b[1]*b[3]-b[0]*b[4])<<" ";
  return 0;
}

C++: #include <iostream>
#include <iomanip>
#include <sstream>
#include <vector>
#include <cmath>

using namespace std;

int main() {
	double a, b, c, d, e, f;

	vector<string> v;
	while (cin >> a >> b >> c >> d >> e >> f) {
		double x, y;

		x = ((c * e) - (b * f)) / ((a * e) - (b * d));
		y = ((c * d) - (a * f)) / ((b * d) - (a * e));

		if (x == 0) {
			x = 0;
		}
		else if (y == 0) {
			y = 0;
		}

		x = x * 1000;
		x = round(x);
		x = x / 1000;

		y = y * 1000;
		y = round(y);
		y = y / 1000;

		stringstream ss;
		ss << fixed << setprecision(3) << x << " " << y;
		v.push_back(ss.str());
	}
	
	for (int i = 0; i < v.size(); i++) {
		cout << v[i] << endl;
	}

	return 0;
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<stdio.h>
using namespace std;



int main(){
  double a,b,c,d,e,f;
  double x,y;
  while(cin >> a >> b >>  c >>  d >>  e >>  f){
    x=(a*f-c*d)/(a*e-b*d);
    y=(c*e-f*b)/(a*e-b*d);
    printf("%.3lf %.3lf \n",x,y);
  }
}