Bonjour !
a)
[tex]3(2x + 4) \\ = 6x + 12[/tex]
b)
[tex]x(2x - 1) \\ = 2 {x}^{2} - x[/tex]
c)
[tex]-5(2x - 3) \\ = - 10x + 15[/tex]
d)
[tex]3x -(-6-1) \\ = 3x + 6 + 1 \\ = 3x + 7[/tex]
e)
[tex]3(x + 2) + 2x + 1 \\ = 3x + 6 + 2x + 1 \\ = 5x + 7[/tex]
f)
[tex]2(5-x) + x(x + 3) - 7 \\ = 10 - 2x + {x}^{2} + 3x - 7 \\ = {x}^{2} + x + 3[/tex]
Bonne soirée
