1) (3-4/7)*х = 5 2/3
3х-4/7х = 5 2/3
2 7/7х-4/7х = 5 2/3
2 3/7х = 5 2/3
17/7х = 17/3
х = 17/3:17/7
х = 17/3*7/17
х = 7/3
х = 2 1/3
Проверяем:
(3-4/7)*2 1/3 = 2 3/7*2 1/3 = 17/7*7/3 =17/3 = 5 2/3
Ответ: 2 1/3.
2) (1 5/6-3/8)*х = 2 1/12
(11/6-3/8)*х = 25/12
(44/24-9/24)*х = 25/12
35/24х = 25/12
х = 25/12:35/24
х = 25/12*24/35
х = 10/7
х = 1 3/7
Проверяем:
(1 5/6-3/8)*10/7 = 35/24*10/7 = 50/24 = 2 2/24 = 2 1/12
Ответ: 1 3/7.
3) (5/8-1/4):х = 1/6
(5/8-2/8):х = 1/6
3/8:х = 1/6
х = 3/8:1/6
х = 3/8*6/1
х = 18/8
х = 9/4
х = 2 1/4
Проверяем:
(5/8-1/4):9/4 = 3/8:9/4 = 3/8*4/9 = 1/6
Ответ: 2 1/4.
4) х*(11/12-1/4) = 3/8
х*(11/12-3/12) = 3/8
х*8/12 = 3/8
х = 3/8:8/12
х = 3/8*12/8
х =36/64
х = 9/16
Проверяем:
9/16*(11/12-1/4)= 9/16*8/12 = 3/8
Ответ: 9/16.