exercice 8: import java.util.Scanner; public class test { public static void main(String[] args){ Scanner sc = new Scanner(System.in); System.out.println("trouver le PCGD de deux entiers : "); System.out.println("Saisissez la valeur de a : "); int a = sc.nextInt(); System.out.println("Saisissez la valeur de b : "); int b = sc.nextInt(); if ( a > 0 && b > 0 ) { System.out.print("PGCD("+a+","+b+") = "); while ( a != b ) { if ( a < b ) b = b - a; else a = a - b; System.out.print("PGCD("+a+","+b+") = "); } System.out.println(a); } }} methode2: import java.util...