Réponse:
A= 3×(-2x)+3×5+(-2x×x)+(-2x×(-3))+5×x+5×(-3)
[tex] - 6x + 15 - 2 {x}^{2} + 6x + 5x - 15 \\ = - 2 {x}^{2} + 5x \\ [/tex]
B
[tex] = 2a \times 3 + 2a \times ( - 4a) + ( - 5) \times 3 + ( - 5 \times ( - 4a) - 2 \times 5 - 2 \times ( - a) \\ [/tex]
[tex] = 6a - 8 {a}^{2} - 15 + 20a - 10 + 2a[/tex]
[tex] = - 8 {a}^{2} + 28a - 25[/tex]
C
