Сэтими уравнениями, вообще про них ниего не рассказывали

1. (2 1/8 + 7/8) - (5/9 - 3/9) = 3 - 2/9 = 2 7/9
2. (3 2/7 + 5/7) - (3/13 - 1/13) = 4 - 2/13 = 3 11/13
3. 5 7/12 + 3 3/12 - 1 1/12 = (5 + 3 - 1) + (7/12 + 3/12 - 1/12) = 7 9/12 = 7 3/4
4. 18 * 6/8 * 27 = 108/8 * 27 = 13,5 * 27 = 364,5
5. 24 * 22 * 25/50 * 72 * 11 =  528 * 0,5 * 792 = 264 * 792 =209088
6. 29 * 13 + 29 * 2/58 * 30 = 377 + 29 * 1/29 * 30 = 377 + 1 * 30 = 407
7. 9 * 32 - 32 * 6/16 * 18 = 288 - 2 * 6/1 * 18 = 288 - 216 = 72
8. 9/14 - (19/35 + 2/21) = 135/210 - (114/210 + 20/210) = 135/210 - 134/2 = 1/210
 9. 4/25 +0,8 - 2/3 = 4/25 + 4/5 - 2/3 = 12/75 + 60/75 - 50/75 = 22/75
10. 3/14 + (11/63 - 5/42) =  27/126 + 22/126 - 15/126 = 34/126 = 17/63

1) 0,4(х - 3) = 0,5(4 + х) - 2,5               2) 0,5(х - 3) = 0,6(4 + х) - 2,6 

0,4х - 1,2 = 2 + 0,5х - 2,5                     0,5х - 1,5 = 2,4 + 0,6х - 2,6 

0,4х - 0,5х = 2 - 2,5 + 1,2                     0,5х - 0,6х = 2,4 - 2,6 + 1,5

- 0,1х = 0,7                                           - 0,1х = 1,3

х = 0,7 : (- 0,1)                                      х = 1,3 : (- 0,1)

х = - 7                                                   х = - 13

3) 0,3(5х - 7) = 3(0,2х + 3,2)                4) 0,9(4у - 2) = 0,5(3у - 4) + 4,4

1,5х - 2,1 = 0,6х + 9,6                          3,6у - 1,8 = 1,5у - 2 + 4,4                         

1,5х - 0,6х = 9,6 + 2,1                          3,6у - 1,5у = - 2 + 4,4 + 1,8

0,9х = 11,7                                            2,1у = 4,2

х = 11,7 : 0,9                                         у = 4,2 : 2,1 

х = 13                                                    у = 2

5) 2(0,6х + 1,85) - 0,7 = 1,3х                6) 0,2(5у - 2) = 0,3(2у - 1) - 0,9

1,2х + 3,7 - 0,7 = 1,3х                           1у - 0,4 = 0,6у - 0,3 - 0,9

1,2х - 1,3х = - 3,7 + 0,7                         1у - 0,6у = - 0,3 - 0,9 + 0,4

- 0,1х = - 3                                              0,4у = - 0,8

х = - 3 : (- 0,1)                                        у = - 0,8 : 0,4

х = 30                                                     у = - 2