Bonsoir
1) Donner l'aire d'un carré de côté 2a.
A = (2a)^2 = 4a^2
2) Développer (puis simplifier l'écriture):
A= 5(x+2) = 5 * x + 5 * 2 = 5x + 10
B = 3 (2z+10)= 3 * 2z + 3 * 10 = 6z + 30
C= a (a + 7) = a * a + a * 7 = a^2 + 7a
D = 6x (2x+1)= 6x * 2x + 6x * 1 = 12x^2 + 6x
E = - 4x ( 5x- 10)= -4x * 5x - 4x * (-10) = -20x^2 + 40x
3) Factoriser (simplifier l'écriture):
F = 5x +5 = 5 * x + 5 * 1 = 5(x + 1)
G = 11t – 6 tv = 11 * t - 6v * t = t(11 - 6v)
H = 12s - 6 = 2s * 6 - 1 * 6 = 6(2s - 1)
I = x² + 3x = x * x + 3 * x = x(x + 3)
J= – 6x² – 12x = -6x * x - 6x * 2 = -6x(x + 2)
4) Donner l'écriture decimale:
10³= 1000
10 -⁴ = 0,0001
102,56×10³= 102,56 x 1000 = 1025600
456×10-⁴= 0,0456
5) Donner d'écriture scientifique
K = 18 365 = 1,8365 x 10^4
L = 0,13 = 1,3 x 10^(-1)
M = 23,6 x 10⁴ = 2,36 x 10^5
N = 0,27 × 10-⁴= 2,7 x 10^(-5)
