Developper puis reduire (2x+1)(x-4) (x-3)(2x-3) (x+2)-(2x-1) (2x-3)(3x+5) (x+3)(2-4x) Mercii

Bonsoir
1) 2x^2-8x+x-4 = 2x^2 - 7 -4
2) 2x^2-3x-6x+9=2x^2 -9x+9
3) x+2-2x+1=-x+3
4) 6x^2+10x-9x-15=6x^2+x-15
5) 2x-4x^2+6-12x=- 4x^2-10x+6

a)(2x+1)(x-4)
=2x²-8x+x-4
=2x²-7x-4
b)(x-3)(2x-3)
=2x²-3x-6x+9
=2x²-9x+9
c)(x+2)-(2x-1)
=x+2-2x+1
=x-2x+2+1
=-x+3
d)(2x-3)(3x+5)
=6x²+10x-9x-15
=6x²+1x-15
e)(x+3)(2-4x)
=2x-4x²+6-12x
=2x-12x-4x²+6
=-10x-4x²+6
bonne chance