Go: package main

import "fmt"

func main() {

	for {
		var a, b, c, d, e, f float64
		var x, y float64
		i, _ := fmt.Scanf("%f %f %f %f %f %f", &a, &b, &c, &d, &e, &f)
		if i != 6 {
			return
		}

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

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

C++: #include <iostream>			//std::cout, std::cin
#include <string>			//std::string,std::to_string(C++11)
#include <vector>			//std::vector
#include <valarray>			//std::valarray
#include <algorithm>		//std::sort
#include <ctime>			//localtime_s
#include <cstdlib>			//abs
#include <cmath>			//abs,std::pow,sqrt,sin,cos,round,floor,ceil
#include <fstream>			//std::ifstream,std::ofstream
#include <iomanip>			//std::setprecision,std::setw,std::setfill
#include <random>			//std::random(C++11)
#include <numeric>			//std::accumulate
#include <functional>		//std::greater
#include <chrono>			//std::chrono(C++11)
#include <bitset>			//std::bitset
#include <queue>			//std::queue

const static double	de_PI	= 3.14159265358979323846;
const static int	de_MOD	= 1000000007;
const static int	de_MAX	= 999999999;

double RoundOff(double a, const int n) {

	for (int i = 0; i < n - 1; i++) {	a *= 10;	}

	if (a > 0) {	a += 0.5;	}
	else {			a -= 0.5;	}

	a = static_cast<int>(a);

	for (int i = 0; i < n - 1; i++) {	a /= 10;	}

	return a;
}

int main(void) {

	//std::ifstream in("123.txt");	std::cin.rdbuf(in.rdbuf());
	//std::ofstream ofs("456.csv");
	//std::chrono::system_clock::time_point t_st = std::chrono::system_clock::now();

	double a = 0, b = 0, c = 0, d = 0, e = 0, f = 0;
	std::vector<double> X, Y;

	while (std::cin >> a) {
		std::cin >> b >> c >> d >> e >> f;
		X.push_back(RoundOff((b*f - c*e) / (b*d - a*e), 4));
		Y.push_back(RoundOff((a*f - c*d) / (a*e - b*d), 4));
	}

	for (unsigned int i = 0; i < X.size(); i++) {
		std::cout << std::fixed << std::setprecision(3) << X[i] << " " << Y[i] << std::endl;
	}

	//std::chrono::system_clock::time_point t_ed = std::chrono::system_clock::now();
	//std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t_ed - t_st).count() << "ms" << std::endl;

}

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

struct vector2{
	float x, y;
	vector2() : x(0), y(0){}
	vector2(float x, float y) : x(x), y(y){}
};

struct sim_elem{
	float a, b, c, d, e, f;
	sim_elem() :a(0), b(0), c(0), d(0), e(0), f(0){}
	sim_elem(float a, float b, float c, float d, float e, float f) :a(0), b(0), c(0), d(0), e(0), f(0){}
};

//	a / d * d
//	ey - by = f - c
//	y / y = (f - c) / y

// ax = -by + c
// ax / a = -(by + c) / a

vector2 sim_equ(sim_elem elem){

	float dx = elem.a / elem.d * elem.d;
	float ey = elem.a / elem.d * elem.e;
	float f = elem.a / elem.d * elem.f;

	float y = ey - elem.b;
	float yr = f - elem.c;
	y = yr / y;

	float ax = -elem.b * y + elem.c;
	float x = ax / elem.a;

	return vector2(x, y);
}

//	sprintf
float placement4(float val){
	char ret[128];
	sprintf(ret, "%.3f", val);
	return (float)atof(ret);
}

int main(){

	sim_elem elem;
	while (1){
		cin >> elem.a >> elem.b >> elem.c >> elem.d >> elem.e >> elem.f;
		if (cin.eof())break;
		vector2 ret;
		ret = sim_equ(elem);
		printf("%.3f %.3f\n", placement4(ret.x) ,placement4(ret.y) );
	}

	return 0;
}

C++: #include <cstdio>
#include <stdlib.h>
#include <math.h>

float a,b,c,d,e,f;
double    round( double val, int precision )
{
    double    ret;
    char    buf[256] = {'\0'};
    char    *p;

    sprintf( buf, "%.*f", precision, val );
    ret = strtod( buf, &p );

    return ret;
}
int main (){
 while(1){
  scanf("%f %f %f %f %f %f",&a,&b,&c,&d,&e,&f);
  double x,y;
  x=(f*b/e-c)/(d*b/e-a);
  y=(f*a/d-c)/(e*a/d-b);
 round(x,4);
 round(y,4);
if(x/1000== -0.000) x=0.000;
if(y/1000== -0.000) y=0.000;
  printf("%.3f %.3f\n",x,y);
  return 0;
  }
}

C++: #include <stdio.h>
#include <vector>
#include <utility>
#include <algorithm>
#include <iostream>
#include <limits>
#include <iomanip>
using namespace std;
#define rep(i,n) for(int i=0;i<n;++i)
#define ld long double
ld a, b, c, d, e, f, x, y;
ld shish(ld a)
{
	a *= 1000;
	a += 0.51;
	a = (ld)((int)a);
	a /= 1000;
	cout << a << endl;
	return a;
}
int main() {
	while (cin >> a >> b >> c >> d >> e >> f) {
		y = (a*f - c*d) / (ld)(a*e - b*d);
		x = (c*e - f*b) / (ld)(a*e - b*d);
		x = shish(x);
		y = shish(y);
		cout << fixed << setprecision(15) << x ;
		cout << " ";
		cout << fixed << setprecision(15) << y<< endl;
	}
	return 0;
}

C++: #define _USE_MATH_DEFINES

#include <iostream>
#include <string>
#include <iomanip>
#include <cmath>
#include <algorithm>
#include <utility>
#include <vector>
#include <numeric>

using namespace std;

int main()
{
	double a, b, c, d, e, f;
	for (; cin >> a >> b >> c >> d >> e >> f;)
	{
		double x, y;
		if (a == 0 || b == 0 || d == 0 || e == 0)
		{
			if (a == 0)
			{
				y = c / b;
				x = (f - e * y) / d;
			}
			else if (b == 0)
			{
				x = c / a;
				y = (f - d * x) / e;
			}

			if (d == 0)
			{
				y = f / e;
				x = (c - b * y) / a;
			}
			else if (e == 0)
			{
				x = f / d;
				y = (c - a * x) / b;
			}
		}
		else
		{
			double a0 = a * e;
			double c0 = c * e;

			double d0 = d * b;
			double f0 = f * b;

			x = (f0 - c0) / (d0 - a0);

			y = (c - a * x) / b;
		}

		cout << fixed << setprecision(3) << x + 0 << " " << y + 0 << endl;

	}
}

C++: #include <iostream>
#include <cstdio>
using namespace std;
int main(){
  double a,b,c,d,e,f;
  double A,B,C;
  double temp;
  int cnt;
  while(scanf("%lf %lf %lf %lf %lf %lf",&a,&b,&c,&d,&e,&f) != EOF){
    A = a;
    B = b;
    C = c;
    b /= a;
    c /= a;
    a = 1;
    e /= d;
    f /= d;
    d = 1;
    b -= e;
    c -= f;
    c /= b;
    C -= c * B;
    C /= A;
    printf("%.3f %.3f\n",C,c);
  }
  return(0);
}

C++: #include <stdio.h>

//ax + by = c
//dx + ey = d

//y = (af-cd)/(ae-bd)
//x = (c-by)/a

int main(void){
double a,b,c,d,e,f;
while(~scanf("%lf%lf%lf%lf%lf%lf",&a,&b,&c,&d,&e,&f))
{
printf("%.3f %.3f\n", (c-b*((a*f-c*d)/(a*e-b*d)))/a, ((a*f-c*d)/(a*e-b*d)));
}
return 0;
}

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


using namespace std;

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

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

using namespace std;

int main()
{
	int 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);
		if (x == -0) x = 0;
		if (y == -0) y = 0;
		printf("%.3lf %.3lf\n", x, y);
	}
	return (0);
}

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 );
	}
}