809*??=800*??+9*??+1

package cskaoyan;
 
public class cskaoyan42 {
    @org.junit.Test
    public void number() {
        long a = 809;
        long b = 0;
 
        for (long i = 10; i < 100; i++) {
            b = a * i;
 
            if (b >= 1000 && b <= 9999 && 8 * i <= 99 && 9 * i >= 100) {
                System.out.println(b + " = 800 * " + i + " + 9 * " + i);
            }
        }
    }
}