bonjour
A=5(2x-3)²-(5x-2)(5x+2)=5(4x²-12x+9)-(25x²-4)=20x²-60x+45-25x²+4=-5x²-60x+49
B=8(2x-1)(2x+1)-4(3x-1)²=8(4x²-1)-4(9x²-6x+1)=32x²-8-36x²+24x-4=-4x²+24x-12
C=(5x-1)-2(5x-1)(x+3)=(5x-1)(1-2x-6)=(5x-1)(-2x-5)=(1-5x)(2x+5)
D=(3x+1)(x-7)+(x+7)(x-7)-2(x-7)
D=(x-7)(3x+1+x+7-2)=(x-7)(4x+6)=2(x-7)(2x+3)