Kylihan
Answered

Développer, puis réduire, si
possible, chaque expression :
A = 2x(x + 3)
B = -7y2(-5 - 2y2)
C = (x + 5)(x + 1)
D = (2x - 5) (x + 4)
E = (4 - a)2
F = (2x + 3)2
G = (4 - 7x)(4 + 7x)
H = (x + 4)(x - 6) + (-1 + x)(x - 7)
I = -3(a2 + 2) - (a - 3)(2a + 7)
J = 4 - (2x + 1)2

Bonjour j’aurais besoin d’aides pour cet exercice merci d’avance

Sagot :

Vins

bonjour

A = 2x(x + 3) = 2 x² + 6 x

B = -7y2(-5 - 2y2)  = 35 y² + 14 y ⁴

C = (x + 5)(x + 1) = x² + x + 5x + 5 = x² +  6 x + 5

D = (2x - 5) (x + 4)  = 2 x² + 8 x - 5 x - 20 = 2 x²  + 3 x - 20

E = (4 - a)2 = 16 - 8 a + a²

F = (2x + 3)2  = 4 x² + 12 x + 9

G = (4 - 7x)(4 + 7x)  =  16 - 49 x²

H = (x + 4)(x - 6) + (-1 + x)(x - 7)  =  x²  - 6 x + 4 x - 24 - x + 7 + x² - 7 x

   =  2 x² - 9 x - 17

I = -3(a2 + 2) - (a - 3)(2a + 7) = - 3 a² - 6 - ( 2 a² + 7 a - 6 a - 21 )

= - 3 a² - 6 - 2 a² - 7 a + 6 a + 21 =  - 5 a² - a + 15

J = 4 - (2x + 1)2  = 4 - ( 4 x²  + 4 x + 1 ) = 4 - 4 x² - 4 x - 1 = - 4 x² - 4 x + 3