Répondre :
A= 3x-6+15-5x = -2x+9
B= 3x+x²-2x-10 = x+x²-10
C= -2x+14-2x²-2+4x²+4= 2x²-2x+16
D= -2x²+10x-x²+x^3 = x^3-3x²+10x
E=-12x^3+18x²-3x-12x²+3x-4x²= 12x^3+2x²
A= 2 (x - 1 ) + 2 (y+2) - 2 (1+z)
= 2x-2+2y+4-2-2z
= 2x+2y-2z
B= 3x - (3-3y) + 3 (z+1)
= 3x-3+3y+3z+3
= 3x+3y+3z
C= (x+y-1) + (x+y+1) - (x+y-z)
= x+y-1+x+y+1-x-y+z
= x+y+z
D= 2 (x-y) + 3 (y-z) + 4 (z-x) + 3x
= 2x-2y+3y-3z+4z-4x+3x
= 5x+y+z
E= x (1-y) + y (1-z) + z (1-x) + xy + yz + xz
= x-xy+y-yz+z-zx+yz+xy+xz
= x+y+z
F= x - [(1-y) - (z+1)]
= x +y+z
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 + 1) + 4 (x² + 1)
C= -2x + 14 -2x² -2 + 4x² +4
C= 2x² -2x +16
D= 2x ( -x + 5) - x² ( 1- x )
D= -2x -x² -1 x² + x(exposant 3)
D= x(exposant 3) -2x² - 2x
E= - 6x (2x² - 3x ) - 3 (x + 4x²) - x( -3 + 4x )
E= -12 x² + 18 x² -3x - 12x² + 3x -4x²
E= -10x²