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
Mathématiques
Kylihan
Question
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
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
1 Réponse
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1. Réponse 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