1) 4 2 (3-__ ) · х = 5___ ; 7 3 2) 5 3 1 (1__ - __ ) · х= 2 ___ ; 6 8 12 3) 5 1 1

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Galasha

12 нояб. 2013 г., 14:22:00 (10 лет назад)

1) (3-4/7)х=5+2/3

17/7х=17/3

х=(17*7)/(3*17)

х=7/3

х=2+1/3 - 2целых одна/третья

в будущем между целой частью и дробью буду букву д писать

2) (1д5/6-3/8)х=2д1/12  

(11/6-3/8)х=25/12

((4*11-3*3)/24)х=25/12

(35/24)х=25/12

х=(25*24)/(12*35)

х=(5*2)/(1*7)

х=10/7

х=1д3/7

3) ((5/8)-(1/4))*(1/х)=1/6

((5-2*1)/8)=х/6

((5-3)/8)=х/6

3/8=х/6

х=3*6/8

х=9/4

х=2д1/4

4) х((11/12)-(1/4))=3/8

х((11-3*1)/12)=3/8

8х/12=3/8

х=(3*12)/(8*8)

х=(3*3)/(2*8)

х=9/16

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Anjelka20

12 нояб. 2013 г., 15:40:30 (10 лет назад)

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.