How do I show the linear composition of two linear equations in Java?(NOT javascript)

Ok, so I want to be able to show the composition of two linear equations for a program I'm working on. Everything is DONE except for this. In the program, there are two classes. One is the LinearEquation class, and the other is the TestLinearEquation class. For the first linear equation (found by the slope and a point), a user enters in the values) for the second linear equation (found with two points) I hard coded that one so it's made inside of the program.

Here's my code:

//LINEAR EQUATION CLASS
public class LinearEquation {
//Declare variables used (slope and y-intercept)
private double slope;
private double yInt;

//"specification" of variables
public LinearEquation(double slope, double yInt)
{
this.slope = slope;
this.yInt = yInt;
}
//define what the slope equals and what the y-intercept equals
public LinearEquation(double xValue, double yValue, double xValue2, double yValue2)
{
slope = (yValue2 - yValue) / (xValue2 - xValue);

yInt = yValue - (slope * xValue);
}
//given an x value, returns appropriate y value
public double xToY(double x)
{
double y = (slope * x) + yInt;

return y;
}
//given a y value, returns appropraite x value
public double ytoX(double y)
{
double x = (y - yInt) / slope;

return x;
}
//find the inverse of the equation
public LinearEquation inverse()
{
double inverseSlope = 1/slope;

double inverseYInt = -yInt/slope;

LinearEquation inverseEquation = new LinearEquation(inverseSlope, inverseYInt);

return inverseEquation;

}
//display equation as slope-intercept form
public String toString()
{
return ("y = " + slope + "x + " + yInt);
}




}

//////////////////////////////////////…


//TEST LINEAR EQUATION CLASS
import java.util.Scanner;
public class TestLinearEquation {

//method for the equation with slope and point given
public static void slopePoint()
{
//Ask for and receive slope for the equation
System.out.println("Please enter the slope for your equation.");
Scanner s = new Scanner(System.in);
double slope = s.nextDouble();

//Ask for and receive y-intercept fore the equation
System.out.println("Please enter the y-intercept for your equation.");
double yInt = s.nextDouble();

//Constructor
LinearEquation equation1 = new LinearEquation(slope, yInt);

//Ask for and receive the x value for the point
System.out.println("Please enter an x value.");
double x1 = s.nextDouble();

//Ask for and receive the y value
double point1y = equation1.xToY(x1);
System.out.println("Y value: " + point1y);

//print the equation
System.out.println("and the equation is " + equation1);

}
//method for the equation with two points given
public static void pointPoint()
{
//constructor
LinearEquation equation2 = new LinearEquation(1,2,3,7);

//equation with two points
double point2y = equation2.xToY(5);
System.out.println("For an equation through (1,2) and (3,7) with an x value of 5,");
System.out.println("Y value: " + point2y);
System.out.println("and the equation is " + equation2);

//give x value when a y value is given
double point3x = equation2.ytoX(15);
System.out.println("For the same equation, with a y value of 15,");
System.out.println("X value: " + point3x);

//inverse of equation
LinearEquation equationInverse = equation2.inverse();
double inverseY = equationInverse.xToY(12);
System.out.println("For the inverse linear equation, and given an x value of 12,");
System.out.println("Y value: " + inverseY);

}
/**
* Method main
*
*
* @param args
*
*/
public static void main(String[] args) {
//Call methods

slopePoint();
pointPoint();



}
}


Please let me know if I need to fix any comments as well

I'm not familiar with javascript, maybe you can get more help on a dedicated javascript forum.

...it's normal java lol (read the title). And I've figured it out and my program is working beautifully!