Réponse :
Bonjour,
B = 2(6x - 4) - (8x² + 2x - 8)
= (2 × 6x - 2 × 4) - (8x² + 2x - 8)
= (12x - 8) - (8x² + 2x - 8)
= 12x - 8 - 8x² - 2x + 8
= -8x² + 12x - 2x - 8 + 8
= -8x² + 10x
[tex]E=(\frac{2}{3}x -8)(7-\frac{4}{5}x)\\=\frac{14}{3}x-\frac{8}{15}x^{2}-56+\frac{28}{5}x\\=-\frac{8}{15}x^{2}+\frac{14}{3}x+\frac{28}{5}x-56\\=-\frac{8}{15}x^{2}+\frac{154}{15}x-56[/tex]
