bonsoir
1) (2x-1)² -(3x-7)² forme de a²-b²
[2x-1-(3x-7)] [2x-1+(3x-7)] = (-x+6)(5x-8
2) 4xcube +12x² = 4x²(x+3)
3) (3x-1)(x-2)+x²-4 = (3x-1)(x-2)+ (x-2)(x+2) = (x-2)(3x-1+x+2) =(x-2)(4x-1)
4) (2x+8)(x+5)+3(2x+10)=(2x+8)(x+5)+6(x+5) = (x+5)(2x+8+6) = (x+5)(2x+14)
