Sagot :
[tex]bonjour\\\\\\\\x + 4 = 12 \\x = 12 - 4 \\x = 8 \\\\x + 5.1 = x + x \\x - x - x = - 5.1\\- x = - 5.1 \\x = 5.1 \\\\\\6 x = x - 15\\6 x - x = - 15\\5 x = - 15\\x = - 3 \\\\[/tex]
[tex]- 14 = 2 x \\- 2 x = 14 \\x = - 7 \\\\5 = 4 x \\- 4 x = - 5 \\x = 5/4\\\\x + 8 = 2 x+ 3 \\x - 2 x = 3 - 8 \\- x = - 5 \\x = 5 \\\\\\[/tex]