Develloppe et réduit les expressions : 3 (x+1)(x-5) 2 (-3-t)(t-7) -(y+5)(3y-6) x(2x-5)(2-x)

3 (x+1)(x-5)
=(3x+3)(x-5)
=3x²-15x+3x-15
=3x²-12x-15

2 (-3-t)(t-7)
=(-6-2t)(t-7)
=-6t+42-2t²-14t
=-2t²-20t+42

-(y+5)(3y-6)
=(-y-5)(3y-6)
=-3y²+6y-15y+30
=-3y²-9y+30

x(2x-5)(2-x)
=(2x²-5x)(2-x)
=4x²-2x³-10x+5x²
=-2x³+9x²-10x