ответ: х= 3/13.
Пошаговое объяснение:
12 * (1 3/4х + 5/8)=8 1/2.
1 3/4х +5/8 = 8 1/2 : 12.
13/4 х+ 5/8 =17/2*1/12.
13/4х + 5/8 = 17/24.
13/4х=17/24 -5/8.
13/4х = (17-15)/24.
13/4х= 2/24=1/12
х= 1/12 : 13/4.
х = 1/12 * 4/13 =1*4/12*13.
х = 3/13.
Пошаговое объяснение:
1) 2/7x= 9/14
х = 9/14 : 2/7
х= 9/14 * 7/2
х= 9/4= 2 1/4
Проверка: 2/7 * 2 1/4 = 9/14
2/7 * 9/4= 9/14
2) 3/8x=6
х= 6 : 3/8
х= 6 :3 * 8
х= 16
Проверка : 3/8 * 16=6
3) 3/x= 2/9
2х=9* 3
2х= 27
х= 13,5
Проверка: 3/13,5 = 2/9
13,5 * 2= 3*9
27=27
4) x: 6/11= 3/7
х= 3/7 * 6/11
х= 18/77
Проверка: 18 /77 : 6/11= 3/7
18/77 *11/6= 3/7
3/7=3/7
5) 18/49:x= 6/35
х= 18/49 * 35/6
х= 15/7 = 2 1/7
Проверка: 18/49 : 15/7=6/35
18/49 * 7/15= 6/35
6/35= 6/35
6) 3/8x=2,4
х= 2 2/5 : 3/8
х= 12/5 * 8/3
х= 32/5= 6 2/5
Проверка: 3/8 * 32/5= 2 ,4
12/5= 2,4
2,4= 2,4
12 * (1 3/4х + 5/8) = 8 1/2
1 3/4x + 5/8 =8 1/2 : 12
1 3/4x + 5/8 = 17/2 * 1/12
1 3/4x + 5/8 = 17/24
1 3/4x = 17/24 - 5/8
1 3/4x = 17/24 - 15/24
1 3/4x = 1/12
x = 1/12 : 1 3/4
x = 1/12 * 4/7
x = 1/21
12 * (1 3/4х + 5/8) = 8 1/2
12 *(7/4x + 5/8) = 17/2
21x+ 15/2 =17/2
21x = 17/2 - 15/2
21x = 1
x=1:21
наверное