Répondre :
A=(4x+5)(4x-5)+(8x-1)²
=16x²-25+64x²+1-16x
=80x²-16x-24
B=(x+2)(2x-3)-(2x+3)²
=2x²+x-6-4x²-12x-9
=-2x²-11x-15
C=2(x-5)²+(x+2)²
=2x²-20x+50+x²+4x+4
=3x²-16x+54
D=2x(x+1)²-(x+4)(2x-1)
=2x(x²+2x+1)-2x²-7x+4
=2x³+2x²-3x+4
=16x²-25+64x²+1-16x
=80x²-16x-24
B=(x+2)(2x-3)-(2x+3)²
=2x²+x-6-4x²-12x-9
=-2x²-11x-15
C=2(x-5)²+(x+2)²
=2x²-20x+50+x²+4x+4
=3x²-16x+54
D=2x(x+1)²-(x+4)(2x-1)
=2x(x²+2x+1)-2x²-7x+4
=2x³+2x²-3x+4