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2014-06-23T18:52:21+02:00
Exercice 48
a) (v-8)(4v+2) = 4v²+ 2v - 32v -16 = 4v² - 30v -16
b) (3x + 7)(2x -5 ) = 6x²-15x +14x -35 = 6x² -x -35 

Exercice 49

a) (2 - 3a)(a + 5)= 2a + 10 - 3a² -15a = -3a² -13a +10
b)(4 + 5x)(2 -x) = 8 -4x +10x -5x² = -5x² + 6x + 8

Exercice 50

a)[ (1/2)x - 1 ][4x+ 2 ] = (1/2)×4×x² + (1/2)×2×x -4x - 2 = 2x² + x - 4x -2 = 2x² -3x -2

b) [(-1/4)x + 1/2 ][ x - 4 ] = (-1/4)x² +( 4/4)x +(1/2)x -4/2 = -x²/4 +x+ x/2 -2 
                                    = (-1/4)x² + (3/2)x - 2           


2014-06-23T19:00:46+02:00
Calculs
(v-8)(4v+2)
4v² +2v -32v -16
4v² -30v -16

(3x +7)(2x -5)
6x² -15x +14x -35
6x² -x -35

(2 -3a)(a+5)
2a +10 -a² -15
-a² +2a -5

(4 +5x)(2-x)
8 -4x +10x -5x²
-5x² +6x +8

(1/2x -1)(4x+2)
4x²/2 +2x/2 -4x -2
4x²/2 +2x/2 -8x/2 -4/2
2x² +x -4x -2
2x² -3x -2