Bonjour,
A= 3(x-2)+5(3-x)
A= 3x-6+15-5x
A= -2x+9
B= x(3+x)-2(x+5)
B= 3x+x²-2x-10
B= x²+x-10
C= -2(x-7)-2(x²+x)+4(x²+1)
C= -2x+14-2x²-2x+4x²+4
C= 2x²-4x+18
D= 2x(-x+5)-x²(1-x)
D= -2x²+10x-x²+x^3
D= x^3-3x²+10x
E= -6x(2x²-3x)-3(x+4x²)-x(-3+4x)
E= -12x^3+18x²-3x-12x²+3x-4x²
E= -12x^3+2x²