Go: package main

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

var sc = bufio.NewScanner(os.Stdin)

func read() string {
	sc.Scan()
	return sc.Text()
}

func main() {
	sc.Split(bufio.ScanLines)
	for sc.Scan() {
		s := strings.Split(sc.Text(), " ")
		a, _ := strconv.ParseFloat(s[0], 64)
		b, _ := strconv.ParseFloat(s[1], 64)
		c, _ := strconv.ParseFloat(s[2], 64)
		d, _ := strconv.ParseFloat(s[3], 64)
		e, _ := strconv.ParseFloat(s[4], 64)
		f, _ := strconv.ParseFloat(s[5], 64)
		x := ((b * f) - (c * e)) / ((b * d) - (a * e))
		y := ((a * f) - (c * d)) / ((a * e) - (b * d))
		if x == 0 {
			fmt.Printf("0.000 %.3f\n", y)
		} else if y == 0 {
			fmt.Printf("%.3f 0.000\n", x)
		} else {
			fmt.Printf("%.3f %.3f\n", x, y)
		}
	}
}

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

int main()
{
	double a, b, c, d, e, f;
	while (cin >> a >> b >> c >> d >> e >> f) {
		double x = (c*e - b*f) / (a*e - b*d);
		double y = (a*f - c*d) / (a*e - b*d);
		//if (x == 0)x = 0;
		//if (y == 0)y == 0;
		printf("%.3f %.3f\n", x, y);
	}
    return 0;
}

C++: #include<stdio.h>
int main(){
  int a,b,c,d,e,f;
  double x,y;
  scanf("%d %d %d %d %d %d",&a,&b,&c,&d,&e,&f);
  y=(c*d-f*a)/(b*d-e*a);
  x=(c-(b*y))/a;
  printf("%.3f %.3f\n",x,y);
  
  return 0;
}

C++: #include <math.h>
#include <iostream>
#include <ios>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <string>

#define YES "YES"
#define NO "NO"
#define space ' '

using namespace std;

void func();

int main(void)
{
	
	func();

	return 0;
}

// using matrix	?????????????????´??????
void func()
{
	int a, b, c, d, e, f;
	double x, y;

	while (cin >> a >> b >> c >> d >> e >> f, !cin.eof()){


		if ((a*e - d*b) == 0)
		{
			cout << 0 << space << 0 << endl;
		}
		else
		{
			x = (e*c - b*f) / (a*e - d*b);
			y = (-d*c + a*f) / (a*e - d*b);

			cout << fixed << setprecision(3);
			cout << x*0.0005 << space << y+0.0005 << endl;
			cout << dec;
		}
	}
}

C++: #include <cstdio>
    #include <iostream>
    using namespace std;
     
    int main() {
    double a,b,c,d,e,f,x,y;
    while(cin>>a>>b>>c>>d>>e>>f){
    if(a==0){
    y=(c+0.0000001)/b;
    x=(f-e*y+0.0000000001)/d;
    }
    else{
    y=(a*f-d*c+0.00000000000001)/(a*e-d*b);
    x=(c-b*y+0.0000000001)/a;
    }
    printf("%.3lf %.3lf\n",x,y);
    }
    return 0;
    }

C++: #include<iostream>

using namespace std;

int main(void)
{
	double a,b,c;
	double d,e,f;
	double delta;
	double delta_one;
	double delta_two;
	double x,y;
	
	while( scanf("%lf %lf %lf %lf %lf %lf",&a,&b,&c,&d,&e,&f) != EOF)
	{
		delta = (a*e) -(b*d);
		delta_one  = (c*e) - (f*b);
		delta_two = (a*f) - (c*d);
		x = delta_one/delta;
		y = delta_two/delta;
		x = x * 1000;
		y = y * 1000;
		x = (int)x;
		y = (int)y;
		x = x/1000;
		y = y/1000;

		printf("%0.3lf %0.3lf\n",x,y);	
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cmath>
 
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 << M[0][2] << " " << M[1][2] << endl; 
}

C++: #include<iostream>
#include<stdio.h>
using namespace std;
int main(){
	float a,b,c,d,e,f,x,y;
	while(cin>>a){
	cin>>b>>c>>d>>e>>f;
	x=(c*e-b*f)/(a*e-b*d);
	y=(c*d-a*f)/(b*d-a*e);
	if(x>-0.0005&&x<=0.0005){
		x=0;
	}
	if(y>-0.0005&&y<=0.0005){
		y=0;
	}
	printf("%.3f %.3f",x,y);
	cout<<endl;
	}
	return 0;
	}

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

#define     MAX_LENGTH     255

using namespace std;

double num_abs_round(const double,const int);

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

	while (cin >> a >> b >> c >> d >> e >> f){
		// Det(係数行列) を計算
		det = (a * e) - (b * d);
		// Det(係数行列) ≠ 0 かどうかをチェック
		if(det == 0){
			cerr << "エラー：この連立方程式の解は存在しないか一意に定まらない" << endl;
			return -1;
		}

		// 解を求める
		x = ((e * c) - (b * f)) / det;
		y = ((a * f) - (d * c)) / det;

		// 整形
		x = num_abs_round(x,3);
		y = num_abs_round(y,3);

		// 表示する
		printf("%.3f %.3f\n",x,y);
	}

	return 0;
}

double num_abs_round(const double num,const int p){
	char num_str[MAX_LENGTH];
	char rtn_str[MAX_LENGTH];
	int i,j;
	bool flag = false;
	double rtn;

	// rtn_str の初期化
	for(i=0;i < ((int)(MAX_LENGTH));i++){
		rtn_str[i] = '\0';
	}

	// 数値を文字列に変換
	sprintf(num_str,"%f\0",num);

	// 符号の確認
	if(num_str[0] == '-'){
		j = 1;
		rtn_str[0] = '0';
	}else{
		j = 0;
	}

	// 小数点の検索 (num_str[j] に '.' が入っている)
	for(;num_str[j] != '.';j++){
		// 小数点がなければ num をそのまま返す
		if(num_str[j] == '\0'){
			return num;
		}
		// rtn_str に num_str をコピー
		rtn_str[j] = num_str[j];
	}

	// '.'をコピー
	rtn_str[j] = '.';

	// 小数点以下 (p + 1) 桁までをコピー
	for(i=1;i <= (p + 1);i++){
		// num が (p + 1) 桁未満だったら num をそのまま返す
		if(num_str[(j + i)] == '\0'){
			return num;
		}
		// rtn_str に num_str をコピー
		rtn_str[(j + i)] = num_str[(j + i)];
	}

	// 小数点以下 (p + 1) 桁を四捨五入
	if(((rtn_str[(j + p + 1)] - '0') >= 0) && ((rtn_str[(j + p + 1)] - '0') <= 4)){
		rtn_str[(j + p + 1)] = '\0';
	}else if((((int)(rtn_str[(j + p + 1)] - '0')) >= 5) && (((int)(rtn_str[(j + p + 1)] - '0')) <= 9)){
		flag = true;
		rtn_str[(j + p + 1)] = '\0';
	}else{
		return 0;
	}

	// rtn_str を数値に変換
	rtn = atof(rtn_str);

	// 五入の場合の処理
	if(flag == true){
		rtn += pow((double)10,(p * (-1)));
	}

	return rtn;
}

C++: #include<iostream>

using namespace std;

int main(){
	//Cramer's Rule
	double a, b, c, d, e, f;

	while(cin >> a >> b >> c >> d >> e>> f) {
		printf("%.3f %.3f\n", (e * c - b * f) / (a * e - b * d), (a * f - c * d) / (a * e - b * d));
	}
	return 0;
}

C++: #include<cstdio>

using namespace std;

int main(){
	int a,b,c,d,e,f;
		while (scanf("%d%d%d%d%d%d",&a,&b,&c,&d,&e,&f) != EOF){
		double x,y,A;
		A = (a*e)-(b*d);
		b *= -1;
		d *= -1;
		
		x = (e*c+b*f)/A;
		y = (d*c+a*f)/A;
	
	printf("%.3lf %.3lf\n",x,y);
		}
	return 0;
}