Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextFloat64() (float64, error) {
	return strconv.ParseFloat(nextString(), 64)
}

func mathRound(f float64) float64 {
	return math.Floor(f + .5)
}

func round(x float64) float64 {
	if math.Abs(x) < 0.001 {
		return 0
	}
	return mathRound(x*1000) / 1000
}

func main() {
	scanner.Split(bufio.ScanWords)
	for {
		a, err := nextFloat64()
		if err != nil {
			break
		}
		b, _ := nextFloat64()
		c, _ := nextFloat64()
		d, _ := nextFloat64()
		e, _ := nextFloat64()
		f, _ := nextFloat64()

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

		fmt.Printf("%.3f %.3f\n", round(x), round(y))
	}
}

C++: //
//  main.cpp
//  CppTest
//
//  Created by Ryu on 2017/02/08.
//  Copyright ?? 2017??´ Ryu. All rights reserved.
//

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cmath>
using namespace std;

int main(int argc, const char * argv[]) {
    // insert code here...
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    float e[10000][6];
    int n = 0;
    float x[10000], y[10000];
    while (cin >> e[n][0] >> e[n][1] >> e[n][2] >> e[n][3] >> e[n][4] >> e[n][5]) {
        float d = e[n][0] * e[n][4] - e[n][1] * e[n][3];
        x[n] = (e[n][4] * e[n][2] - e[n][1] * e[n][5]) / d;
        y[n] = (0 - e[n][3] * e[n][2] + e[n][0] * e[n][5]) / d;
        //printf("d: %f, x: %.4f, y: %.4f\n", d, x[n], y[n]);
        n++;
    }
    
    
    for(int i = 0; i < n; i++){
        if(x[i] == -0){
            x[i] = 0;
        }
        if(y[i] == -0){
            y[i] = 0;
        }
        printf("%.3f %.3f\n", x[i], y[i]);
    }
    
    
    return 0;
}

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

using namespace std;

typedef struct Shiki{
  double a,b,c;//ax+by=c
  double x,y;
};

Shiki Equation (Shiki, Shiki);

Shiki clean={clean.a=0,clean.b=0,clean.c=0,clean.x=0,clean.y=0};

main(){
  Shiki shiki1,shiki2;
  vector<Shiki> ans;
  int i=0;
  
  while(cin){

    cin>>shiki1.a>>shiki1.b>>shiki1.c>>shiki2.a>>shiki2.b>>shiki2.c;
    ans.push_back(Equation(shiki1,shiki2));
    i++;
    shiki1 = clean;
    shiki2 = clean;
  }
 
  for(int j = 0; j < i-1 ;j++){
    cout<< fixed << setprecision(3) << ans[j].x << " " << ans[j].y << endl; 
  }
}

Shiki Equation (Shiki A, Shiki B){
  Shiki ans,preA;
  int x,y,aa,ba;
  
  preA = A;

  aa = A.a;
  ba = B.a;
  
  A.a *= ba;
  A.b *= ba;
  A.c *= ba;
  
  B.a *= aa;
  B.b *= aa;
  B.c *= aa;
  
  ans.a = 0;
  ans.b = A.b - B.b;
  ans.c = A.c - B.c;
  ans.y = ans.c / ans.b;
  ans.x = (preA.c - preA.b*ans.y)/preA.a;
  
  if((int)(ans.y*1000)%10 >= 5)ans.y += 0.0001;
  if((int)(ans.y*1000)%10 >= 5)ans.x += 0.0001;
  
  return ans;
}

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

int main()
{
	
	// 係数行列
	double A[2][2];
	
	// 定数ベクトル
	double  B[2];
	
	// 解ベクトル
	double x[2];
	
	
	double a, b, c, d, e, f;
	// 入力の最後まで処理する
	while(cin >>a >>b >>c >>d >>e >>f){
	A[0][0] = a;
	A[0][1] = b;
	A[1][0] = d;
	A[1][1] = e;
	
	B[0] = c;
	B[1] = f;
	
	
	
	int i,j,k;
	double tmp;
	
	// 前進消去
	for(i=0;i<1;i++){
		for(j=i+1;j<2;j++){
			for(k=i+1;k<2;k++){
				A[j][k] = A[j][k] - (A[j][i]/A[i][i])*A[i][k];
			}
			B[j] = B[j] - (A[j][i]/A[i][i])*B[i];
		}
	}
	
	// 後退代入
	for(i=1;i>=0;i--){
		tmp = B[i];
		for(j=i+1;j<2;j++){
			tmp = tmp - A[i][j]*x[j];
		}
		x[i] = tmp/A[i][i];
	}
	
	printf("%4lf %4lf\n", x[0], x[1]);
	
	}
	
	return 0;
}

C++: #include <iostream>
#include <sstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <climits>
#include <cfloat>
using namespace std;

int main()
{
    const int TMP = 10000;
    for(;;){
        int a,b,c,d,e,f;
        if(!(cin >> a >> b >> c >> d >> e >> f))
            return 0;
        int x = TMP * (c*e - b*f) / (a*e - b*d);
        int y = TMP * (c*d - a*f) / (b*d - a*e);
        int xSign = (x>=0? 1:-1);
        int ySign = (y>=0? 1:-1);
        x = abs(x);
        y = abs(y);

        if(x % 10 >= 5)
            x += 10;
        x /= 10;
        if(xSign == -1 && x > 0)
            cout << '-';
        printf("%d.%04d ", x/TMP, x%TMP);

        if(y % 10 >= 5)
            y += 10;
        y /= 10;
        if(ySign == -1 && y > 0)
            cout << '-';
        printf("%d.%04d\n", y/TMP, y%TMP);
    }
}

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

using namespace std;

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

	cin >> a >> b >> c >> d >> e >> f;

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

	cout << fixed << setprecision(3) << x << " " << y << endl;
	//printf("%.3f %.3f\n", x, y);
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include <cstdio>
#include <iostream>
#include <vector>
#include <list>
#include <map>
#include<string>
#include <algorithm>
#include <functional>
#include <cmath>
using namespace std;
typedef vector <int> ivector;


int main(){
	float a, b, c, d, e, f;
	while (scanf("%f%f%f%f%f%f",&a,&b,&c,&d,&e,&f)!=EOF)
	{

		
		float x = (c*e - b*f) / (a*e - b*d);
		float y = (c*d - a*f) / (b*d - a*e);
		printf("%.3f %.3f\n", x, y);
	}
	

	return 0;
}

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

int main(){
  int i;
  float x[6];
  int y1, y2, re1, re2;

  while(cin >> x[0]){
    for(i=1; i<6; i++){
      cin >> x[i];
    }

    //normalize
    x[1]/=x[0]; x[2]/=x[0]; x[0]=1;

    //subtraction
    x[4]-=x[3]*x[1]; x[5]-=x[3]*x[2]; x[3]=0;

    //normalize
    x[5]/=x[4]; x[4]=1;

    //subtraction
    x[2]-=x[1]*x[5]; x[1]=0;

    y1=(int)x[2]*10000; y2=(int)x[5]*10000;
    re1=y1%10; re2=y2%10;
    if(re1>4) y1-=re1;
    else y1+=10-re1;
    if(re2>4) y2-=re2;
    else y2+=10-re2;
    printf("%f %f\n", (float)y1/10000.0f, (float)y2/10000.0f);
  }

  return 0;
}

C++: #include <iostream>
#include <cmath>
#include <algorithm>
#include <string>
using namespace std;
int main() {
    double a,b,c,d,e,f;
    double x,y;
    while (cin >>a>> b>>c>>d>>e>>f) {
            
        x=(c*e-b*f)/(a*e-b*d);
       
        y=(a*f-c*d)/(a*e-b*d);
        printf("%.3f %.3f\n",x,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;
                int p,q;
                p = a * e - d * b;
                q = c * e - f * b;
                x = q / p;
                p = b * d - e * a;
                q = c * d - f * a;
                y = q / p;
                std::cout << std::fixed << std::setprecision(3) << x << " " << y << std::endl;
        }
        return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

const double EPS=1e-12;
typedef vector<double>vec;
typedef vector<vec>mat;

/// Ax=b
vec gauss_jordan(const mat& A,const vec& b){
    int n=A.size();
    mat B(n,vec(n+1));

    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)B[i][j]=A[i][j];

    for(int i=0;i<n;i++)B[i][n]=b[i];

    for(int i=0;i<n;i++){
        int pivot=i;
        for(int j=i+1;j<n;j++){
            if(abs(B[j][i])<abs(B[pivot][i]))pivot=j;
        }
        swap(B[i],B[pivot]);
        if(abs(B[i][i])<EPS)return vec();

        for(int j=i+1;j<=n;j++)B[i][j]/=B[i][i];
        for(int j=0;j<n;j++){
            if(i==j)continue;
            for(int k=i+1;k<=n;k++)B[j][k]-=B[j][i]*B[i][k];
        }
    }

    vec x(n);
    for(int i=0;i<n;i++)x[i]=B[i][n];
    return x;
}

int main(){
    mat A(2,vec(2));
    vec b(2);
    while(true){
        for(int i=0;i<2;i++){
            if(scanf("%lf%lf%lf",&A[i][0],&A[i][1],&b[i])==EOF)return 0;
        }

        vec x=gauss_jordan(A,b);
        if(x.size()<2)return 0;
        printf("%lf %lf\n",x[0],x[1]);
    }
    return 0;
}