28 : 4*30 450:5*2 81:9*80 400*2 : 100 140:70*10 15*4:10 560:7*4 50*60:100 45: (13-4) 8*8-6*7 ( * это умножить) Математика 3 класс 2-я часть стр 15 № 11. И какая отгатка

28 : 4 * 3 0 = 7 * 4 / 4 * 30 = 7 * 1 / 1 * 30 = 7 / 1 * 30 = 7 * 30 = 210

450 : 5 * 2 = 90 * 5 / 5 * 2 = 90 * 1 / 1 * 2 = 90 / 1 * 2 = 90 * 2 = 180

81 : 9 * 80 = 9 * 9 / 9 * 80 = 9 * 1 / 1 * 80 = 9 / 1 * 80 = 9 * 80 = 720

400 * 2 : 100 = 400 * 2 / (1 / 100) = 400 * 100 / 2 = 400 * 50 * 2 / 2 = 400 * 50 * 1 / 1 = 400 * 50 = 8000

140 : 70 * 10 = 2 * 10 = 20

15 * 4 : 10 = 60 / 10 = 6

560 : 7 * 4 = 8 * 4 = 32

50 * 60 : 100 = 3000 / 100 = 3 0 * 100 / 100 = 30 * 1 / 1 = 30

45 : (1 3 - 4) = 45 / 9 = 9 * 5 / 9 = 1 * 5 / 1 = 5

8 * 8 - 6 * 7 = 64 - 42 = 22