(5a + 7)(4a + 1) (3a - 4)(4a-11) (- 4x + 17)(-3x - 21) (2a - b)(-7b + 4a) developer et réduire svp

Réponse:

=(5a+7)(4a+1)

=(5a x4a) (7+1)

=20a x 8

=(3a-4)(4a-11)

=(3a x 4a) (-4-11)

=12a x - 15

=(-4x + 17) (-3x - 21)

=(-4x x - 3x) (17 x - 21)

=12x x - 357

=(2a - b) (-7b + 4a)

=(2a x 4a) (-b x - 7b)

= 8a x 7b