bonjour
A(x) =2x(x-3)-5(x-1)(x+2)
A ( x ) = 2 x² - 6 x - 5 ( x² + 2 x - x - 2 )
A ( x) = 2 x² - 6 x - 5 x² - 10 x + 5 x + 10
A ( x) = - 3 x² - 11 x + 10
C(x)=(x+3)(-2x+1)-3x(x-2)
C (x) = - 2 x² + x - 6 x + 3 - 3 x² + 6 x
C (x) = - 5 x² + x + 3
B(x) = - x(x+2)-3(x^2 - 2) +2^2 - 6
B (x) = - x² - 2 x - 3 x² + 6 + 4 - 6
B (x) = - 4 x² - 2 x + 4
D(x)=(7x-3)(-10x - 2)+5(x+2)
D (x) = - 10 x² - 14 x + 30 x + 6 + 5 x + 10
D (x) = - 10 x² + 21 x + 16
Bonsoir,
A(x) =2x(x-3)-5(x-1)(x+2)
= 2x² -6x -[(5x-5)(x+2)]
= 2x² -6x -(5x+10 -5x -10)
= 2x² -6x -5x-10 +5x +10
= 2x² -6x
C(x)=(x+3)(-2x+1)-3x(x-2)
= -2x² +x -6x +3 -3x² +6x
= -5x² +x +3
B(x) = - x(x+2)-3(x² - 2) +2² - 6
= -x² -2x -3x² +6 +4 -6
= -4x² -2x +4
D(x)=(7x-3)(-10x - 2)+5(x+2)
-70x² -14x +30x +6 +5x +10
= -70x² +21x +16