// Math.java
package com.comsoft.ch03.p2;// 創(chuàng)建另一個包
public class Math {// Math為public類，可跨訪問
	public double add(double x, double y) { return x + y; }
	public double subtract(double x, double y) { return x - y; }
	public double multiply(double x, double y) { return x * y; }
	public double divide(double x, double y) { return x / y; }
}