Bonjour,
Calculer:
C= x²-(-2x²)+(-7x²)-2x²= x²+2x²-7x²-2x²= - 6x²
D= - 4x+x²+6+5x²+3x-10+8x²+2x= 14x²+x-4
E= -4-3x+2x²-4x+x²+x²-x= 4x²-8x-4
F= 2x³+4+6x²-x+2x-9x³-3x²+9x= - 7x³+3x²+10x+4.
G= 1/4 x²- 3x/2 - 1/2 x²-4/5 +5x/4= (x²-2x²)/4 - (2*3x+5x)/4- 4/5
= -1/4 x²-1/4 x - 4/5 ⇔ - x²/4 - x/4 - 4/5 .
