Réponse:
[tex]1)5x + 8 = 0 \\ 5x = - 8 \\ x = \frac{ - 8}{5} [/tex]
[tex]2)3x + 4 = 2x + 9 \\ 3x - 2x = 9 - 4 \\ x = 5[/tex]
[tex]3)2x + 4 = 5x - 1 \\ 2x - 5x = - 1 - 4 \\ - 3x = - 5 \\ x = \frac{5}{3} [/tex]
[tex]4) - 3x + 5 = 0.25 \\ - 3x = 0.25 - 5 \\ - 3x = - 4.75 \\ x = \frac{19}{12} [/tex]
[tex]5)5(x - 1) + 3(2 - x) = 0 \\ 5x - 5 + 6 - 3x = 0 \\ 2x + 1 = 0 \\ 2x = - 1 \\ x = \frac{ - 1}{2} [/tex]
[tex]6)8(4 - 3x) + 1 = 53 - 3(x - 5) \\ 32 - 24x + 1 = 53 - 3x + 15 \\ 33 - 24x = 68 - 3x \\ - 24x + 3x = 68 - 33 \\ - 21x = 35 \\ x = - \frac{5}{ 3} [/tex]
[tex]7)(x + 2)(x + 1) = (x + 4)(x - 5) \\ {x}^{2} + x + 2x + 2 = {x}^{2} - 5x + 4x - 20 \\ x + 2x + 2 = - 5x + 4x - 20 \\ 3x + 2 = - x - 20 \\ 3x + x = - 20 - 2 \\ 4x = - 22 \\ x = \ - \frac{11}{2} [/tex]
Et voilà
