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 <bits/stdc++.h>
#define INT(name) int name; scanf("%d",&name);
#define VINT(name,n) vector<int> name(n); for(int i = 0;i < n;i++) scanf("%d",&name[i]);

using namespace std;

int main(int argc, char const *argv[]){
	int a,b,c,d,e,f;
	while(cin >> a >> b >> c >> d >> e >> f){
		cout.precision(3);
		double y = (double)(a*f-c*d)/(double)(a*e-b*d);
		double x = (double)(c-b*y)/(double)a;
		cout << std::fixed << x;
		cout << ' ' << std::fixed << y << endl;
	}
}

C++: #include <iostream>
#include <cstdio>
#ifndef repeat
#define repeat(i,n) for (int i = 0; i < (n); ++i)
#endif
#ifndef repeat_from
#define repeat_from(i,m,n) for (int i = (m); i < (n); ++i)
#endif
#ifndef repeat_one
#define repeat_one(i,n) for (int i = 1; i <= (n); ++i)
#endif
#ifndef repeat_rev
#define repeat_rev(i,n) for (int i = (n)-1; 0 <= i; --i)
#endif
#ifndef foreach
#define foreach(it, cont) for (typeof(cont.begin()) it = cont.begin(); it != cont.end(); ++it)
#endif
#include <vector>
#include <cmath>
#ifndef repeat
#define repeat(i,n) for (int i = 0; i < (n); ++i)
#endif
#ifndef repeat_from
#define repeat_from(i,m,n) for (int i = (m); i < (n); ++i)
#endif
#ifndef repeat_one
#define repeat_one(i,n) for (int i = 1; i <= (n); ++i)
#endif
#ifndef repeat_rev
#define repeat_rev(i,n) for (int i = (n)-1; 0 <= i; --i)
#endif
#ifndef foreach
#define foreach(it, cont) for (typeof(cont.begin()) it = cont.begin(); it != cont.end(); ++it)
#endif
#ifndef LIB_DEBUG_HPP
#define LIB_DEBUG_HPP
#ifdef DEBUG
#include <cassert>
#define debug(a) a
#else
#define debug(a)
#endif
#endif
#include <iostream>

// a11x1 + a12x2 + ... + a1m-1xm-1 = a1m
// a21x1 + a22x2 + ... + a2m-1xm-1 = a2m
//      ...        ...            ...
// an1x1 + an2x2 + ... + anm-1xm-1 = anm
std::vector<double> gaussian_elim(std::vector<std::vector<double> > a) {
    const int n = a.size();
#ifdef DEBUG
    assert (0 < n);
#endif
    const int m = a[0].size();
#ifdef DEBUG
    repeat (i, n) assert ((int)a[i].size() == m);
    assert (n == m-1);
#endif
    // make an upper diagonal matrix
    repeat (i, n) {
        {
            int pivot = -1;
            repeat_from (j, i, n) {
                const double eps = 1e-16;
                if (eps < std::abs(a[j][i])) { pivot = j; break; }
            }
#ifdef DEBUG
            assert (pivot != -1);
#endif
            if (pivot != i) std::swap(a[i], a[pivot]);
        }
        repeat_from (j, i+1, m) a[i][j] /= a[i][i];
        a[i][i] = 1;
        repeat_from (j, i+1, n) {
            repeat_from (k, i+1, m) {
                a[j][k] -= a[j][i] * a[i][k];
            }
            a[j][i] = 0;
        }
    }
    // gather the solutions
    std::vector<double> result(n);
    repeat_rev (i, n) {
        result[i] = a[i][m-1];
        repeat_from (j, i+1, n) {
            result[i] -= a[i][j] * result[j];
        }
    }
    return result;
}
using namespace std;
int main() {
    // ax + by = c
    // dx + ey = f
    vector<vector<double> > v(2, vector<double>(3));
    vector<double> w;
    while (true) {
        repeat (i,2) repeat (j,3) cin >> v[i][j];
        if (cin.fail()) break;
        w = gaussian_elim(v);
        printf("%.3lf %.3lf\n", w[0], w[1]);
    }
    return 0;
}

C++: #include <stdio.h>
#include <iostream>
#include <algorithm>
#include <cmath>

using namespace std;

//substitution
int main() {

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

	while(1) {
		cin >> a >> b >> c >> d >> e >> f;
		if ( cin.eof() ) {
			break;
		}
	//a*x + b*y = c  and d*x + e*y = f
	
	 float y =(a*f - c*d)/(a*e - b*d);
	 float x =(c*e - b*f)/(a*e - b*d);

	printf("%.3f %.3f\n", x,y);
	}

    return 0;
}

C++: #include<iostream>
#include<cmath>
#include<string>

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

C++: #include <iostream>
#include <string>
#include <vector>
#include <sstream>

using namespace std;

using DataSet = vector<double>;

void readInputData(vector<string> input_data){
    string buff;
    while(getline(cin, buff)){
        input_data.push_back(buff);
    }
}

void _parseString(const string& input_data, DataSet& data_set) {
    data_set.resize(6);

    stringstream ss;
    ss << input_data;
    ss >> data_set[0] >> data_set[1] >> data_set[2]
        >> data_set[3] >> data_set[4] >> data_set[5];
}

void parseString(const vector<string>& input_data, vector<DataSet>& data_set) {
    data_set.resize(input_data.size());
    for(int i = 0; i < input_data.size(); ++i) {
        DataSet buff;
        _parseString(input_data[i], buff);
        data_set[i] = buff;
    }
}

double determinant2d(const DataSet& data){
    return data[0] * data[4] - data[1] * data[3];
}

void inverse2d(DataSet& data){
    double t = data[0];
    data[0] = data[4];
    data[4] = t;

    data[1] = -data[1];
    data[3] = -data[3];
}


void calculateXY(const DataSet& data, double det, vector<double>& result){
    result.resize(2);

    result[0] = (data[0] * data[2] + data[1] * data[5]) / det;
    result[1] = (data[3] * data[2] + data[4] * data[5]) / det;
}

void solve(vector<DataSet>& data_set){
    for(int i = 0; i < data_set.size(); ++i){
        vector<double> buff;

        double det = determinant2d(data_set[i]);

        inverse2d(data_set[i]);

        calculateXY(data_set[i], det, buff);

        cout << buff[0] << " " << buff[1] << endl;
    }
}



void doAllProcess(){
    vector<string> input_data;
    readInputData(input_data);

    vector<DataSet> data_set;
    parseString(input_data, data_set);

    solve(data_set);
}


int main(){
    doAllProcess();
    return 0;
}

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

using namespace std;
double sg(double n); 
int main()
{
	int a[1000],b[1000],c[1000],d[1000],e[1000],f[1000];
	float x[1000],y[1000];
	int w_x,w_y;
	int len=0;
	while (cin >> a[len] >> b[len] >> c[len] >> d[len] >> e[len] >> f[len])
		len++;

	for (int i=0; i < len; i++) {
		x[i] =  ((e[i] * c[i] - b[i] * f[i]) / (e[i] * a[i] - b[i] * d[i]));
		y[i] =  ((c[i] * d[i] - f[i] * a[i]) / (b[i] * d[i] - a[i] * e[i]));
	}
	for (int i=0; i < len; i++) {
		printf("%.3lf %.3lf\n",sg(x[i]),sg(y[i]));
	}
	return 0;
}
double sg(double n)
{
	int w;
	n = n * 10000.0;
	w = (int)n % 10;
	n /= 10000.0;
	if (w > 4) 
		n += 0.001;
	return n;
}