Пошаговое объяснение:
4.
1) 35/64 : 2,5 =
35/64 : 2. 5/10 =
35/64 : 25/10 = 35/64 * 10/25 = 7/32 * 5/5 =
7/32 * 1 = 7/32
2) 2. 3/16 : 7/32 =
35/16 : 7/32 = 35/16 * 32/7 = 5/1 * 2/1 = 10/1 = 10
3) 16 : 32 = 16/32 = 1/2
4) 10 : 1/2 = 10 * 2/1 = 20/1 = 20
5) 1/11 * 0,825 =
1/11 * 825/1000 = 1/11 * 33/40 = 1/1 * 3/40 = 3/40
6) 20 * 3/40 = 60/40 =
3/2 = 1. 1/2
ответ: 1. 1/2
5.
1) 4,8 * 5/12 = 4. 8/10 * 5/12 = 48/10 * 5/12 = 4/2 * 1/1 = 4/2 = 2
2) 2 * 23/60 = 1 * 23/30 = 23/30
3) 23/30 : 2,3 = 23/30 :
2. 3/10 = 23/30 : 23/10 =
23/30 * 10/23 = 10/30 = 1/3
4) 1. 1/6 : 1/3 = 7/6 : 1/3 =
7/6 * 3/1 = 21/6 = 7/2 = 3,5
5) 21 : 3,5 = 6
6) 6 : 5 = 6/5 = 1. 1/5 или 1,2
ответ: 1. 1/5
х - 1 = 20 - 2х
х + 2х = 20 + 1
3х = 21
х = 21/3
х = 7