Bonjour,vous pouvez m’aider svp merci d’avance !!! Exercice 5 Réduire les expressions suivantes : A = (x + 3) - (x + 5) - (x-7) B=-(a + 4) + (-a-5) + (3 - a) C

Bonsoir,

A = (x + 3) - (x + 5) - (x-7)

= x+3-x-5-5-x +7

= -x +5

B=-(a + 4) + (-a-5) + (3 - a)

= -a-4 -a-5+3-a

= -3a -6

C = -(x²-x) - (x - 1)-(1 - x²)

= -x²+x²-x+1-1+x²

= x² -x

D = x² - (3x² – 5x²) + (x² – 8x²) - 2x²

= x²-3x²+5x²+x²-8x²-2x²

= -6x²