Struggling to find point of intersection using two lines in y = mx + b form

Question

The method:

    public static int[] FindIntersectionPoint(int[] p0, int[] p1, int[] p2, int[] p3) {
    //line 1 equation
    double m1 = (double) (Math.abs(p0[1] - p1[1])) / (double) (Math.abs(p0[0] - p1[0])); //slope
    double b1 = p0[1] - (m1 * p0[0]); //y axis intercept
    DC.drawLine(p0[0], p0[1], p1[0], p1[1]);

    //line 2 equation
    double m2 = (double) (Math.abs(p2[1] - p3[1])) / (double) (Math.abs(p2[0] - p3[0])); //slope
    double b2 = p2[1] - (m2 * p2[0]); //y axis intercept
    DC.drawLine(p2[0], p2[1], p3[0], p3[1]);

    //Intersection points
    double intersectX = (double)(b2 - b1) / (double)(m1 - m2);
    double intersectY = 0;
    System.out.println(intersectX); //is -18.181818181818205 which is way off

    return new int[] {(int)intersectX, (int)intersectY};
}

Method call:

int point[] = FindIntersectionPoint(new int[]{200, 100}, new int[]{300, 400}, new int[]{500, 50}, new int[]{200, 400});

I've checked and the m1, m2, b1, b2 variables are all calculated correctly and the formula for the xIntercept: (b2 - b1) / (m1 - m2) worked on paper but the program calculates -18.181818181818205 which is definitely not the answer.

Here is a visualization of whats going on:

Answer 1

Possible bug could be in this line:

double b1 = p0[1] - (m1 * p0[0]); //y axis intercept

You are saving operation on int to double , where the decimal digits will be always 0. You are sure, that this calculation is good?

Cast at least one of the ints to double before dividing.