Réponse :
A = 18x² + 30x - 12x - 20
A = 18x² + 18x - 20
B = -8x² + 6x + 28x - 21
B = -8x² + 34x - 21
C = 6x + 12 - 8x² - 16x
C = -8x² - 12x + 12
D = a² - 2 * a * b + b²
D = 25x² - 20x + 4
Explications étape par étape
Réponse:
A= 6x×3x+6x×5-4×3x-4×5
= 9x^2+30x-12x-20
=9x^2+18x-20
B= -2x×4c-2x×(-3)+7×4x+7×(-3)
= 8x+6x+28x-21
= 42x-21
C= -3×(-2x)-3×(-4)+4x×(-2x)+4x×(-4)
= 6x +12-8x-16
=-2x-4
D= 5x×5x+5x×(-2)-2×5x-2×(-2)
= 25x^2-10x-10x+4
= 25x^2-20x+4
