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

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 = 8000140 : 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