Répondre :
Réponse :
a) 5(2x+3) (9x+4)
=(10x+15) (9x+4)
=90x²+40x+135x+19
=90x²+175x+19
b) 2(3x+1)(6x-1)
=(6x+2)(6x-1)
=36x²-6x+12x-2
=36x²+6x-2
c) 3(5x-2)(7x-3)
=(15x-6)(7x-3)
=105x²-45x-42x+18
=105x²-87x+18
d) 3(4x-5)(2x-7)
=(12x-15)(2x-7)
=24x²-84x-30x+105
=24x²-114x+105
e)-2(3x+5)(8x-9)
=(-6x-10)(8x-9)
=-48x²+54x-80x+90
=-48x²-26x+90
f) -7(2x-3)(4x-9)
=(-14x+21)(4x-9)
=-56x²+126x+84x-189
=56x²+210x-189
Explications étape par étape :