(1/4 + 1/6) (2/5 - 1/2) =(3/12 + 2/12) (4/10 - 5/10) =5/12 * (-1/10) =-5/120 =-1/24
Ответ: -1/24
(4/7 - 3/2) (1/13 - 1/4) =(-8/14 + 21/14) (4/52 - 13/52) =13/14 * (-9/52) =-117/728
Ответ: -117/728
4 2/3 + 1/4 (1 7/9 - 1/9) =14/3 + 1/4 (16/9 - 1/9) =14/3 + 1/4 * 15/9 =14/3 + 5/12 =56/12 + 5/12 =61/12
Ответ: 61/12
5 1/7 - 1/7 (1 3/4 + 1/4) =36/7 - 1/7 (7/4 + 1/4) =36/7 - 1/7 * 8/4 =36/7 - 8/7 =28/7 =4
Ответ: 4
(1/4 + 1/6) (2/5 - 1/2) =
(3/12 + 2/12) (4/10 - 5/10) =
5/12 * (-1/10) =
-5/120 =
-1/24
Ответ: -1/24
Для второго выражения:(4/7 - 3/2) (1/13 - 1/4) =
(-8/14 + 21/14) (4/52 - 13/52) =
13/14 * (-9/52) =
-117/728
Ответ: -117/728
Для третьего выражения:4 2/3 + 1/4 (1 7/9 - 1/9) =
14/3 + 1/4 (16/9 - 1/9) =
14/3 + 1/4 * 15/9 =
14/3 + 5/12 =
56/12 + 5/12 =
61/12
Ответ: 61/12
Для четвертого выражения:5 1/7 - 1/7 (1 3/4 + 1/4) =
36/7 - 1/7 (7/4 + 1/4) =
36/7 - 1/7 * 8/4 =
36/7 - 8/7 =
28/7 =
4
Ответ: 4