Sagot :
(x+1)²
4x²-20x+25-x²=3x²-20x+25
(3x+2)²
4x²-2x+1-(x²-6x+9) = 4x²-2x+1-x²+6x-9 = 3x²+4x-8
Identité remarquable x²+2x+1
(2x-5)²-x²
9x²+12x+4
(2x-1)²-(x-3)²
(x+1)²
4x²-20x+25-x²=3x²-20x+25
(3x+2)²
4x²-2x+1-(x²-6x+9) = 4x²-2x+1-x²+6x-9 = 3x²+4x-8