developper , puis reduire les expression. A =(5+7)(3-x) . b=(2x+3)(x-5)-(4x-1)(x-9) . c=5(x-7)+ (4x -2)(7-3x) . d= (x +3)(x-5) -(-1 +x) (x- 9) . e = (5x -1
Mathématiques
ruthmaniaj
Question
developper , puis reduire les expression. A =(5+7)(3-x) . b=(2x+3)(x-5)-(4x-1)(x-9) . c=5(x-7)+ (4x -2)(7-3x) . d= (x +3)(x-5) -(-1 +x) (x- 9) . e = (5x -1)(5x - 2) - (-7 + 2x (-4+3x)
1 Réponse
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1. Réponse maudmarine
Développer, puis réduire les expressions
A =(5+7)(3-x)
A = 15 - 5x + 21 - 7x
A = - 12x + 36
b=(2x+3)(x-5)-(4x-1)(x-9)
b = (2x² - 10x + 3x - 15) - (4x² - 36x - x + 9)
b = 2x² - 10x + 3x - 15 - 4x² + 36x + x - 9
b = 2x² - 4x² - 10x + 3x + 36x + x - 15 - 9
b = - 2x² + 30x - 24
c=5(x-7)+ (4x -2)(7-3x)
c = 5x - 35 + (28x - 12x² - 14 + 6x²)
c = 5x + 35 + 28x - 12x² - 14 + 6x²
c = - 12x² + 6x² + 5x + 28x + 35 - 14
c = - 6x² + 33x + 21
d= (x +3)(x-5) -(-1 +x) (x- 9)
d = x² - 5x + 3x - 15 - (- x + 9 + x² - 9x)
d = x² - 5x + 3x - 15 + x - 9 - x² + 9x
d = x² - x² - 5x + 3x + 9x + x - 15 - 9
d = 8x - 24
e = (5x - 1) (5x - 2) - (- 7 + 2x (- 4 + 3x)
e = (25x² - 10x - 5x + 2) - (28 - 12x - 8x + 6x²)
e = 25x² - 10x - 5x + 2 - 28 + 12x + 8x - 6x²
e = 25x² - 6x² - 10x - 5x + 12x + 8x + 2 - 28
e = 19x² + 5x - 26