a) 42 = 6 7, 21 = 3 7, 28 = 4 * 7b) 42 = 40 + 2, 21 = 20 + 1, 28 = 20 + 8c) 42 - 1 = 41, 21 - 2 = 19, 28 - 8 = 20
a) 42 = 6 7, 21 = 3 7, 28 = 4 * 7
b) 42 = 40 + 2, 21 = 20 + 1, 28 = 20 + 8
c) 42 - 1 = 41, 21 - 2 = 19, 28 - 8 = 20