Решение системы уравнений

import java.util.Arrays;
 
public class Circle {
    private final double r;
    private final PointMiddle middle;
 
    public Circle(double r, PointMiddle middle) {
        this.r = r;
        this.middle = middle;
    }
 
    public PointMiddle[] getPoints(Circle circle) {
        PointMiddle[] points = null;
        double d = Math.sqrt(Math.pow(Math.abs(this.middle.getX() - circle.middle.getX()), 2) +
                Math.pow(Math.abs(this.middle.getY() - circle.middle.getY()), 2));
        if (d < this.r + circle.r && d > Math.abs(this.r - circle.r)) {
            double a = (Math.pow(this.r, 2) - Math.pow(circle.r, 2) + Math.pow(d, 2)) / (2 * d);
            double h = Math.sqrt(Math.pow(this.r, 2) - Math.pow(a, 2));
            double x0 = this.middle.getX() + a * (circle.middle.getX() - this.middle.getX()) / d;
            double y0 = this.middle.getY() + a * (circle.middle.getY() - this.middle.getY()) / d;
 
            points = new PointMiddle[2];
            double x = x0 + h * (circle.middle.getY() - this.middle.getY()) / d;
            double y = y0 - h * (circle.middle.getX() - this.middle.getX()) / d;
            points[0] = new PointMiddle(x, y);
 
            x = x0 - h * (circle.middle.getY() - this.middle.getY()) / d;
            y = y0 + h * (circle.middle.getX() - this.middle.getX()) / d;
            points[1] = new PointMiddle(x, y);
        } else {
            System.out.println("not solution");
        }
        return points;
    }
 
    @Override
    public String toString() {
        return String.format("R = %.2f; middle = %s;", this.r, this.middle);
    }
}
 
class PointMiddle {
    private final double x;
    private final double y;
 
    public double getX() {
        return x;
    }
 
    public double getY() {
        return y;
    }
 
    public PointMiddle(double x, double y) {
        this.x = x;
        this.y = y;
    }
 
    @Override
    public String toString() {
        return String.format("[%.2f, %.2f]", this.x, this.y);
    }
}
 
class CircleTest {
    public static void main(String[] args) {
        Circle first = new Circle(10, new PointMiddle(1, 1));
        Circle second = new Circle(10, new PointMiddle(6, 6));
 
        System.out.println("Circle 1:\n" + first);
        System.out.println("Circle 2:\n" + second);
 
        PointMiddle[] points = first.getPoints(second);
        System.out.println("Points:\n" + Arrays.toString(points));
    }
}