Bonjour
Développer les expressions suivantes :
(X+3)(5x-4)+(x+3)²
= 5x² - 4x + 15x - 12 + x² + 6x + 9
= 5x² + x² - 4x + 15x + 6x - 12 + 9
= 6x² + 17x - 3
(4x+1)²-(3x-2)(4x+1)
= 16x² + 8x + 1 - (12x² + 3x - 8x - 2)
= 16x² + 8x + 1 - 12x² - 3x + 8x + 2
= 16x² - 12x² + 8x + 8x - 3x + 1 + 2
= 4x² + 13x + 3
(4x+5)(4x-5)*(x+2)(4x+5)
=(16x² - 25) (4x² + 5x + 8x + 10)
= 64x⁴ + 80x³ + 128x³ + 160x² - 100x² - 125x -200x - 250
= 64x⁴ + 208x³ + 60x²- 325x - 250
(X-5)²-(x-5)(7-2x)
= x² - 10x + 25 - (7x - 2x² - 35 + 10x
= x² - 10x + 25 - 7x + 2x² + 35 - 10x
= x² + 2x² - 10x - 10x - 7x + 25 + 35
= 3x² - 27x + 60
(X-1)(2x+5)-(x-1)²
= 2x² + 5x - 2x - 5 - (x² - 2x + 1)
= 2x² + 5x - 2x - 5 - x² + 2x - 1
= 2x² - x² + 5x - 5 - 1
= x² + 5x - 6
