Сократите: 12*21/35*15; 72*11/33*30; 25*17*44/51*8*75; 8*3+8*23/3*16; 17*48/17*16-9*16; 14*5-14*3/21*9+21*3

а) 12 * 21/35 * 15 = 108.
    12 * 21/35 = (12 * 21)/35 = 252/35 (уменьшаем на 7) = 36/5.
    36/5 * 15 = (36 * 15)/5 = 540/5 = 108.
б) 72 * 11/33 * 30 = 720.
    72 * 11/33 = (72 * 11)/33 = 792/33 = 24.
    24 * 30 = 720.
в) 25 * 17 * 44/51 * 8 * 75 = 220000.
    25 * 17 = 425.
    425 * 44/51 = (425 * 44)/51 = 18700/51 (сокращаем на 17) = 1100/3.
8 * 75 = 600.
    1100/3 * 600 = (1100 * 600)/3 = 660000/3 = 220000.
г) 8 * 3 + 8 * 23/3 + 16 = 101 1/3.
    8 * 3 = 24.
    8 * 23/3 = (8 * 23)/3 = 184/3.
    24 + 184/3 + 16 = (72 + 184 + 48)/3 = 304/3 = 101 1/3.
д) 17 * 48/17 * 16 - 9 * 16 = 624.
    17 * 48/17 * 16 = (17 * 48 * 16)/17 = 13056/17 = 768.
    9 * 16 = 144.
    768 - 144 = 624.
е) 14 * 5 - 14 * 3/21 * 9 + 21 * 3 = 115.
    14 * 5 = 70.
    21 * 3 = 63.
    14 * 3/21 * 9 = (14 * 3 * 9)/21 = 378/21 = 18.
    70 - 18 + 63 = 115.