Вычисли значения следующих произведений: а) 31 * 3 = (30 + 1) * 3 = 30 * 3 + 1 * 3=? 72 * 4 =? 56 * 5 =? 92 * 6 =? б)

а) 31 * 3 = (30 + 1) * 3 = 30 * 3 + 1 * 3=90 +3 = 9372 * 4 = (70+ 2) * 4 = 280 + 8 = 28856 * 5 = (50 + 6) * 5 = 250 + 30 = 28092 * 6 = (90 + 2) * 6 = 540 + 12 = 552б) 234 * 3 = (200 + 30 + 4) * 3 =600 + 90 + 12 = 702412 * 5 = (400 + 10 + 2) * 5 = 2000 + 50 10 = 2050506 * 4 = (500 + 6) * 4 = 2000 + 24 = 2024.