Question

Решите все пж очень надо

Answer 1

1) 2х/7 = (3 + х)/8

2х * 8 = 7(3 + х)

16х = 21 + 7х

16х - 7х = 21

9х = 21

х = 21/9

х = 2 3/9 = 2 1/3

Ответ:  2 1/3.

2) 7х/5 = (2 + х)/9

7х * 9 = 5(2 + х)

63х = 10 + 5х

63х - 5х = 10

58х = 10

х = 10/58 = 5/29

Ответ: 5/29.

3) (2 - х)/7 = (3 + х)/14

14(2 - х) = 7(3 + х)

28 - 14х = 21 + 7х

- 14х - 7х = 21 - 28

- 21х = - 7

21х = 7

х = 21 : 7

х = 3

Ответ: 3.

4) (7 - х)/5 = (2 + х)/15

15(7 - х) = 5(2 + х)

105 - 15х = 10 + 5х

- 15х - 5х = 10 - 105

- 20х = - 95

20х = 95

х = 95/20

х = 4,75

Ответ:  4,75.

5) х/14 + х/16 = 5

16х + 14х = 5 * 14 * 16

30х = 1120

х = 1120/30

х = 37 1/3

Ответ: 37 1/3.

6) х/15 + х/27 = 3

27х + 15х = 3 * 15 * 27

32х = 1215

х = 1215 : 32

х = 37 31/32

Ответ: 37 31/32.

7) х/3 + (х + 1)/7 = (х - 2)/6

х * 7 * 6 + (х + 1) * 3 * 6 = (х - 2) * 3 * 7

42х + 18х + 18 = 21х - 42

60х - 21х = - 42 - 18

39х = - 60

х = - 60/39

х = - 1 21/39

х = - 1 7/13

Ответ: - 1 7/13.

8) х/2 + (х - 1)/4 = (х + 2)/9

х * 4 * 9 + (х - 1) * 2 * 9 = (х + 2) * 2 * 4

36х + 18х - 18 = 8х + 16

54х - 8х = 16 + 18

46х = 34

х = 34/46

х = 17/23

Ответ: 17/23.