[tex]4 x = - 8 \\x = - 2\\\\x + 7 = 2 \\x = 5 \\\\8 x = 48 \\x = 6 \\\\20 x = 20 \\x = 1 \\\\- 7 x = 42 \\x = - 6 \\\\12 - x = 9 \\- x = - 3 \\x = 3[/tex]

Réponse:

4x = -8

x = -8/4 = -2

x + 7 = 2

x = 2 -7 = -5

8x = 48

x = 48/8 = 6

20%x = 20

x = 20/20 x 100 = 1 x 100 = 100

-7x = 42

x = 42/-7 = -6

12 - x = 9

-x = 9 - 12 = -3

x = 3