#include<bits/stdc++.h>
int n;
double a[106][106];
signed main(){
	scanf("%d",&n);
	for (int i=1;i<=n;i++) for (int j=1;j<=n+1;j++) scanf("%lf",&a[i][j]);
	for (int i=1,max=1;i<=n;max=++i){
		for (int j=i+1;j<=n;j++) if (fabs(a[j][i])>fabs(a[max][i])) max=j;
		if (fabs(a[max][i])<1e-7) for (int j=1;j<=n;j++){
			if (fabs(a[j][n+1]<1e-7)) printf("0\n");
			else printf("1\n");
			return 0;
		}
		if (i!=max) std::swap(a[i],a[max]);
		for (int j=n+1;j>=i;j--) a[i][j]/=a[i][i];
		for (int j=1;j<=n;j++) if (j!=i){
			for (int k=n+1;k>=i;k--) a[j][k]-=a[j][i]*a[i][k];
		}
	}
	for (int i=1;i<=n;i++){
		if (a[i][n+1]==-0.00) printf("x%d=0.00\n",i);
		else printf("x%d=%.2lf\n",i,a[i][n+1]);
	}
	return 0;
}

从模板来的，改了一些，结果一直60pts求解