Chapter 1 Question 1.13, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

(Algebra: solve 2 * 2 linear equations) You can use Cramer’s rule to solve the following 2 * 2 system of linear equation: 

ax + by = e cx + dy = f x = ed - bf/ ad - bc y = af - ec/ ad - bc 

Write a program that solves the following equation and displays the value for x and y: 

                    3.4x + 50.2y = 44.5 

                    2.1x + .55y = 5.9

Answer

//Program - 13

public class HelloWorld

{

    public static void main(String[] args)

    {

       

        System.out.println("3.4x + 50.2y = 44.5");

        System.out.println("2.1x +  .55y =  5.9");

        System.out.println("x = (44.5 * .55) - (50.2 * 5.9)");

        System.out.println("    ----------------------------");

        System.out.println("    (3.4  * .55) - (50.2 * 2.1)");

        System.out.println((((44.5 * .55) - (50.2 * 5.9)) /

                             ((3.4 * .55) - (50.2 * 2.1))));

        System.out.println(" ");

        System.out.println("y = (3.4 * 5.9) - (44.5 * 2.1)");

        System.out.println("    --------------------------");

        System.out.println("    (3.4 * .55) - (50.2 * 2.1)");

        System.out.println((((3.4 * 5.9) - (44.5 * 2.1)) /

                            ((3.4 * .55) - (50.2 * 2.1))));

    }

}

OUTPUT

3.4x + 50.2y = 44.5

2.1x +  .55y =  5.9

x = (44.5 * .55) - (50.2 * 5.9)

   ----------------------------

   (3.4  * .55) - (50.2 * 2.1)

2.623901496861419

y = (3.4 * 5.9) - (44.5 * 2.1)

   --------------------------

   (3.4 * .55) - (50.2 * 2.1)

0.7087397392563978