最佳拟合直线

import java.util.*;
public class Main {
	
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		while(n>0) {
			double x[]=new double[123456];
			double y[]=new double[123456];
			int i;
			for(i=0;i<n;i++) {
				x[i]=sc.nextDouble();
				y[i]=sc.nextDouble();
			}
			double sum1=0,sum2=0,sum3=0,sum4=0;
			for(i=0;i<n;i++) {
				sum1+=x[i]*x[i];
				sum2+=x[i];
				sum3+=y[i];
				sum4+=x[i]*y[i];
			}
			double fza=n*sum4-sum2*sum3;
			double fzb=sum3*sum1-sum2*sum4;
			double fm=n*sum1-sum2*sum2;
			
			//System.out.println(fza+","+fzb+" "+fm);
			System.out.printf("%.3f\n%.3f\n",fza/fm,fzb/fm);
			
			n--;
		}
		sc.close();
	}
}