Réponse:
A=
[tex] \frac{ - 5 + \frac{2}{7} }{ \frac{11}{30} - \frac{2}{10} } = \frac{ \frac{ - 35}{7} + \frac{2}{7} }{ \frac{11}{30} - \frac{6}{30} } [/tex]
[tex] = \frac{ \frac{ - 33}{7} }{ \frac{5}{30} } [/tex]
[tex] = \frac{ - 33}{7} \times \frac{30}{5} = - \frac{33}{7} \times 6 = - \frac{198}{7} [/tex]
B = ( 8x - 3)(5-4x) - (6x + 7)
B = 40x - 32x² - 15 + 12x - 6x - 7
B = -32x² + 46x - 22
C = (5x - 2)² + 7 (5 x - 2)-(10x-4)
C = (5x - 2)² + 7 (5 x - 2)- 2(5x-2)
C = (5x-2)[(5x-2) + 7 - 2]
C = (5x-2)(5x+3)
