线性方程组的求解C++

问题很不明确！

#include<iostream>

using namespace std;

float hanglieshi(float a1[],float b1[],float c1[])
{
float result=a1[0]*b1[1]*c1[2]+a1[1]*b1[2]*c1[0]+a1[2]*b1[0]*c1[1]-a1[2]*b1[1]*c1[0]-a1[1]*b1[0]*c1[2]-b1[2]*c1[1]*a1[0];
return result;
}

int main()
{
float a[3];//放a1 a2 a3
float b[3];//放 b1 b2 b3
float c[3];//放c1 c2 c3
float d[3];//放d1 d2 d3

do
{
cout<<"a1x+b1y+c1z=d1 a2x+b2y+c2z=d2 a3x+b3y+c3z=d3\n";
cout<<"请输入a1 b1 c1 d1:";
cin>>a[0]>>b[0]>>c[0]>>d[0];
cout<<"请输入a2 b2 c2 d2:";
cin>>a[1]>>b[1]>>c[1]>>d[1];
cout<<"请输入a3 b3 c3 d3:";
cin>>a[2]>>b[2]>>c[2]>>d[2];

float aa=hanglieshi(a,b,c);
float xx=hanglieshi(d,b,c);
float yy=hanglieshi(a,d,c);
f