18 * 40 = 18 * 4 * 10
18 * 40 = 18 * (4 * 10)
18 * 40 = 18 * 40
72 * 14 < 72 * 10 * 4
72 * 14 < 72 * (10 * 4)
72 * 14 < 72 * 40
36 * 5 * 10 > 36 * 15
36 * (5 * 10) > 36 * 15
36 * 50 > 36 * 15
98 * 21 = 98 * 3 * 7
98 * 21 = 98 * (3 * 7)
98 * 21 = 98 * 21