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2013-11-17T12:29:47+01:00
Bonjour

Exercice I

E = 3/5 -1/5 x (5/2 +2)
E = 3/5 -1/5 x (5/2 + 4/2) = 3/5 -1/5 x 9/2
E = 3/5 - 9/10
E = 6/10 -9/10 = -3/10

F = 3 x 10² +1,2 x 10^-5 sur 15 x 10²  (^ = puissance)
F = 3 x 1.2 x 10^-3 sur 15 x 10²
F = 3.6 x 10^-3 sur 15 x 10²
F = 0.24 x 10^-5
Ecriture scientifique = 2.4 x 10 x 10^-5 = 2.4 x 10^-4

Exercice II
A = (x-3)² + (x-3)(8x-5)
A = x² -6x +9 + 8x² -5x -24x +15
A = 10x² -35x +24

A = (x-3)(x-3) + (8x -5)
A = (x-3)( x -3 +8x -5)
A = (x-3)( 9x -8)
Pour x = 2
A = (2-3)(18-8) = -1 x 10 = -10