Go: package main

import (
        "fmt"
        "bufio"
        "os"
)

func main() {
        var a, b, c, d, e, f float64
        sc := bufio.NewScanner(os.Stdin)
        for sc.Scan() {
                fmt.Sscanf(sc.Text(), "%f %f %f %f %f %f", &a, &b, &c, &d, &e, &f)

                det := a*e - b*d
                x := (e*c - b*f) / det
                y := (a*f - c*d) / det
                fmt.Printf("%04f %04f\n", x, y)
        }
}

C++: #include <iostream>
#include <stdio.h>
#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){
	//	ax+by=c > y=(c-ax)/b
	// 	dx+ey=f > y=(f-dx)/e
	//	> (c-ax)/b=(f-dx)/e
	//	c/b-(a/b)x=f/e-(d/e)
	// 	(d/e)x-(a/b)x=f/e-c/b
		double tmp=(d/e)-(a/b);
		x=((f/e)-(c/b))/tmp;
		y=(c-(a*x))/b;
		printf("%.3lf %.3lf\n", x , y );
	}
}

C++: #include<bits/stdc++.h>
#include<cstdio>
#include<sstream>
#include<cstdlib>
#include<cctype>
#include<cmath>
#include<algorithm>
#include<set>
#include<queue>
#include<stack>
#include<list>
#include<iostream>
#include<fstream>
#include<numeric>
#include<string>
#include<vector>
#include<cstring>
#include<map>
#include<iterator>

using namespace std;
#define EPS 1e-9
#define MAX 505
#define pb push_back
#define mp make_pair
#define ins insert
#define fi first
#define se second
#define pi acos(-1.0)
#define mod 100000007
#define inf 2147483647
#define ll long long int
#define sss stringstream
#define oss ostringstream
#define iss istringstream
#define llu long long unsigned

#define _sq(a) (a)*(a)
#define sz(a) ((int)a.size())
#define gcd(a,b)    __gcd(a,b)
#define lcm(a,b) ((a)*((b)/gcd(a,b)))
#define _max3(a,b,c) max(a, max(b,c))
#define _min3(a,b,c) min(a, min(b,c))
#define FOR(i, n) for(i=0; i<(int)n; i++)
#define FOR1(i, n) for(i=1; i<=(int)n; i++)
#define mem(a) memset(a, 0, sizeof(a))
#define _set(a) memset(a,-1,sizeof(a))
#define FORI(i, a, b) for(i=a; i>=(int)b; i--)
#define FORab(i, a, b) for(i=a; i<=(int)b; i++)
#define popcount(n) __builtin_popcount(n)
#define popcountl(n) __builtin_popcountll(n)
#define sort_rev(a) sort(a.rbegin(), a.rend())
#define sort_all(a) sort(a.begin(), a.end())
#define dis_twopoints(x1,y1,x2,y2) sqrt(_sq(x1-x2) + _sq(y1-y2))
#define foreach(i,n) for(__typeof((n).begin())i =(n).begin();i!=(n).end();i++)

//If Long Long (mask & (1LL << k))
#define check(mask, k) (mask & (1 << k))
#define set1(mask, k) (mask | (1 << k))
#define set0(mask ,k) (mask & (~(1<<k)))

#define SD(a) scanf("%d",&a)
#define SLF(a) scanf("%lf",&a)
#define SC(a) scanf("%c",&a)
#define SS(a) scanf("%s",a)
#define SLLD(a) scanf("%lld", &a)
#define Si64(a) scanf("%I64d", &a)

#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)
int main()
{
    double a,b,c,d,e,f,x,y,fl,clx,cly;
    while((cin>>a>>b>>c>>d>>e>>f)!=EOF)
    {
        fl=(e*a-b*d);
        clx=c*e-b*f;
        if(clx==0)
            x=0.0;
        else
            x=clx/fl;
        cly=f*a-c*d;
        if(cly==0)
            y=0.0;
        else
            y=cly/fl;
        printf("%.3lf %.3lf\n",x,y);
    }
    return 0;
}

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

double* solve_equations(int *a)
{
	// クラメルの公式を用いる
	int data_size=sizeof(a[0]);
	/*cout << "data_size=" << data_size << endl;
	cout << "a=" << a << endl;
	cout << "*(a + data_size*1)=" << *(a + 1) << endl;
	cout << "*(a + data_size*0) * *(a + data_size*4)" << *(a + data_size*0) * *(a + data_size*4) << endl; */
	int z = *(a + 0) * *(a + 4) 
		  - *(a + 1) * *(a + 3);
	int x = *(a + 2) * *(a + 4)
		  -	*(a + 1) * *(a + 5);
	int y = *(a + 0) * *(a + 5)
		  - *(a + 2) * *(a + 3); 
	double ax,ay;
	/*cout << "x=" << x << endl;
	cout << "y=" << y << endl;*/
	ax = pow(z,-1)*x;
	ay = pow(z,-1)*y;
	
	/* cout << ax << endl;
	cout << ay << endl; */
	double ans[2] = {ax,ay};
	return ans;
}

int main()
{
	int n[6];
	int s;
	int i=0;
	while (cin >> s){
		if (i == 5){
			n[i]=s;
			/* for (int j=0;j<=5;j++)
			{
				cout << "n[" << j << "]=" << n[j] << endl;
			}*/
			double* an;
			an = solve_equations(n);
			/* printf("%.3lf",*(an+0));
			cout << " " << endl;
			printf("%.3lf",*(an+1)); */
			if (an[1] == 0)
				cout << fixed << setprecision(3) << an[0] << " " << 0.000 << endl;
			else if(an[0] == 0)
				cout << fixed << setprecision(3) << 0.000 << " " << an[1] << endl;
			else
				cout << fixed << setprecision(3) << an[0] << " " << an[1] << endl;

			i = 0;}
		else{
			n[i]=s;
			i++;
		}
	}
	return 0;
			// cout << l[0]  endl;
}

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

int main(){
	double a,b,c,d,e,f;
	while(cin>>a>>b>>c>>d>>e>>f){
		double det = a*e-b*d;
		double x = 1/det*(c*e - b*f);
		double y = 1/det*(-c*d + a*f);	
		if(x < 0.0000001) x = 0;
		if(y < 0.0000001) y = 0;

		cout << fixed << setprecision(3) << x << ' ' << y <<endl;
	}
	return 0;
}

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


int main() {
	float a,b,c,d,e,f;
	while(cin >> a >> b >> c >> d >> e >> f){
		float e2 =e*(a/d);
		float f2 =f*(a/d);
		d=a;
		float y=(c-f2)/(b-e2);
		float x=(c-b*y)/a;
		cout <<fixed;
		cout << setprecision(3) << x << " " << y << endl;

	}
	return 0;
}

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

int main() {
	int number[6];
	double x, y;
	while (cin 
		>> number[0] >> number[1] >> number[2]
		>> number[3] >> number[4] >> number[5]) {
		y = (number[2] * number[3] - number[0] * number[5])
			/ (number[1] * number[3] - number[0] * number[4]);
		x = (number[2] - number[1] * y) / number[0];
		cout << fixed << setprecision(3) << x << flush;
		cout << " " << flush;
		cout << fixed << setprecision(3) << y << endl;
	}
	return 0;
}

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

C++: #include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define all(a)  (a).begin(),(a).end()
#define vi vector<int>
#define pb push_back
#define INF 999999999

const double EPS = 1e-8;
typedef vector<double> vd;
typedef vector<vd> mat;

//Ax=b????§£??? A?????£?????????
//?§£??????or????????§?????? ??´????????????0???vector?????????
vd gauss_jordan(const mat& A, const vd& b){
    int n=A.size();
    mat B(n,vd(n+1));
    rep(i,n) rep(j,n) B[i][j]=A[i][j];
    
    //??????A????????????b?????????????????????????????????
    rep(i,n) B[i][n] = b[i];
    
    rep(i,n){
        //??¨????????????????????°????????°?????¶???????????§????????????i??????????????£?????????
        int pivot = i;
        for(int j=i;j<n;j++){
            if(abs(B[j][i])>abs(B[pivot][i]))pivot = j;
        }
        swap(B[i],B[pivot]);
        
        //?§£??????or????????§??????
        if(abs(B[i][i])<EPS)return vd();
           
        //??¨????????????????????°????????°???1?????????
        for(int j=i+1;j<=n;j++)B[i][j]/=B[i][i];
        rep(j,n){
            if(i!=j){
                //j??????????????°????¶????
                for(int k=i+1;k<=n;k++)B[j][k]-=B[j][i]*B[i][k];
            }
        }
    }
    vd x(n);
    //??????????????????b????§£?????????
    rep(i,n)x[i]=B[i][n];
    return x;
}


int main(){
    int a,b,c,d,e,f;
    while(cin>>a>>b>>c>>d>>e>>f){
        vd vec;
        vec.pb(c);
        vec.pb(f);
        mat mvec;
        vd x,y;
        x.pb(a);
        x.pb(b);
        y.pb(d);
        y.pb(e);
        mvec.pb(x);
        mvec.pb(y);
        vd res = gauss_jordan(mvec, vec);
        printf("%.10lf %.10lf\n",res[0],res[1]);
    }
}