Bonjour, E= (3x+2)² - (3x+2)(x+7) a. Développer et réduire E b. Factoriser E c. Calculer E pour x = 1/2

Bonjour,
a
E = 9x²+12x+4 - (3x²+21x+2x+14) = 9x²+12x+4-3x²-23x-14 = 6x²-11x-10
b
E = (3x+2)[3x+2-(x+7)] = (3x+2)(2x-5)
c
Pour x = 1/2, E = (3/2+2)(1-5) = 7/2(-4) = -14

bonjour,

E= (3x+2)² - (3x+2)(x+7)
e = 9x²+12x+4 -(3x²+21x+2x+14)
e = 9x²+12x+4 -3x²-23x-14
e = 6x²-11x-10

E= (3x+2)² - (3x+2)(x+7)
(3x+2)(3x+2-x-7)
(3x+2)(2x-5)

e =6x²-11x-10
e = 6(1/2)² -11(1/2) -10
e = 6(1/4) -11/2 -10
e = 6/4 -11/2-10
e = 3/2 -11/2 -10
e = -8/2 -10
e = -4-10
e = -14