Verified answer

№ 1145.

1) - 6(х + 2) = 4х - 17                         2) (18х - 19) - (4 - 7х) = - 73

- 6х - 12 = 4х - 17                               18х - 19 - 4 + 7х = - 73 

- 6х - 4х = - 17 + 12                            18х + 7х = - 73 + 19 + 4

- 10х = - 5                                            25х = - 50

х = - 5 : (- 10)                                       х = - 50 : 25

х = 0,5                                                  х = - 2

3) 10х + 3(7 - 2х) = 13 + 2х                4) - 3(4 - 5у) + 2(3 - 6у) = - 3,9

10х + 21 - 6х = 13 + 2х                       - 12 + 15у + 6 - 12у = - 3,9 

10х - 6х - 2х = 13 - 21                         15у - 12у = - 3,9 + 12 - 6

2х = - 8                                                 3у = 2,1

х = - 8 : 2                                              у = 2,1 : 3

х = - 4                                                   у = 0,7

№ 1146.

1) 9(х - 1) = х + 15                2) (11х + 14) - (5х - 8) = 25

9х - 9 = х + 15                       11х + 14 - 5х + 8 = 25

9х - х = 15 + 9                       11х - 5х = 25 - 14 - 8

8х = 24                                  6х = 3 

х = 24 : 8                               х = 3 : 6

х = 3                                      х = 0,5

3) 12 - 4(х - 3) = 39 - 9х             4) 2(3х + 5) - 3(4х - 1) = 11,8

12 - 4х + 12 = 39 - 9х                 6х + 10 - 12х + 3 = 11,8

- 4х + 9х = 39 - 12 - 12               6х - 12х = 11,8 - 10 - 3

5х = 15                                       - 6х = - 1,2

х = 15 : 5                                    х = - 1,2 : (- 6)

х = 3                                           х = 0,2

№ 1147.

1) 0,8(4х + 5) = - 3,2                2) - 2,4(7 - 9у) = - 48

3,2х + 4 = - 3,2                        - 16,8 + 21,6у = - 48

3,2х = - 3,2 - 4                          21,6у = - 48 + 16,8

3,2х = - 7,2                               21,6у = - 31,2

х = - 7,2 : 3,2                            у = - 31,2 : 21,6 

х = - 72/32                                у = - 312/216

х = - 2 8/32                               у = - 1 96/216

х = - 2 1/4                                 у = - 1 4/9