10 - x = 13
8 + 4x = 20
12 : x + 18 = 32
123 - 15x = 80

прошу решите

10 - х = 13

х = 10 - 13

х = - 3

8 + 4х = 20

4х = 20 - 8

4х = 12

х = 12 : 4

х = 3

12 : х + 18 = 32

12 : х = 32 - 18

12 : х = 14

х = 12 : 14

х = 12/14

х = 6/7

123 - 15х = 80

15х = 123 - 80

15х = 43

х = 43/15

х = 2 целых 13/15