a)
660 = 2 * 330 = 2 * 2 * 165 = 2 * 2 * 3 * 55 = 2 * 2 * 3 * 5 * 11
б)
1350 = 2 * 675 = 2 * 3 * 225 = 2 * 3 * 3 * 75 = 2 * 3 * 3 * 5 * 15 = 2 * 3 * 3 * 5 * 5 * 3