Bonjour
A = 2x -3(x+5)
A = 2x-3x-15
A = -x-15
B = (x+5)(x-4)
B = x²-4x+5x-20
B = x²+x-24
C = (x-4)²
C = x²-2x*4+4²
C = x²-8x+16
D = (2x-5)(3x-4)
D = 6x²-8x-15x+20
D = 6x²-23x+20
E = (2x-5)²-2x(x-7)
E = 4x²-2*2x*5+5²-2x²+14x
E = 2x²-20x+25+14x
E = 2x²-6x+25