Line graphing program

// ROWS 9
// COLUMNS 9

import java.util.*;
import java.text.*;

public class Proj3 {

public static void main(String[] args) {
Scanner input = new Scanner(System.in);



System.out.print("Enter x1:   ");
double x1 = input.nextInt();
System.out.print("Enter y1:   ");
double y1 = input.nextInt();
System.out.print("Enter x2:   ");
double x2 = input.nextInt();
System.out.print("Enter y2:   ");
double y2 = input.nextInt();
double slope = (y2-y1) / (x2-x1);
double intercept = y1-slope*x1;
System.out.printf("y = " + "%.2f" + "x" + " + " + "%.2f\n", slope,intercept    );
System.out.println();
int i;
int j;

for (i=9; i>=0; i--) {
for (j=13; j>=0; j--) {
if (j==i+4) {
System.out.print(j-4);
}

}


System.out.println();

}

}



}