Réponse :
bonjour
1)A = (x² + xy)² − (x² − xy − 2y²)² on remarque un forme a² - b² = (a-b)(a+b)
A = (x² + xy -(x² - xy - 2y²))(x² + xy + x² - xy -2y²)
A = (x² + xy - x² + xy + 2y²)(2x² - 2y²)
A= (2xy + 2y²)*2(x² - y²)
A = 2y*(x + y)*2(x - y)(x + y)
A = 4y(x +y)²(x - y)
2)B = (2x² − 18)(x − 2) − (x² − 9)(2x − 1) + 3 − x
B = 2(x² - 9)(x - 2) - (x² - 3²)(2x -1) -( -3 + x)
B = 2(x² -3²)(x-2) - (x -3)(x+ 3)(2x -1) - (x -3)
B = 2 (x -3)(x +3)(x -2) - (x -3)(x+3)(2x -1) - (x - 3)
B = (x-3)[ 2(x +3)(x -2) - (x+3)(2x -1) - 1]
B = (x - 3)[(x +3) (2(x -2) - (2x -1)) -1]
B = (x -3)[(x + 3)(2x - 4 - 2x + 1) - 1]
B = (x -3)[(x +3)(-3) - 1]
B = (x-3)(-3x - 9 -1)
B = (x -3)(-3x - 10)
3)C = 16x² − 9 + (4x + 3)(x − 1) + 5x(x − 2) − 4(x − 2)
C = (4x)² - 3² +(4x +3)(x -1) + (x-2)(5x - 4)
C = (4x -3)(4x +3) + (4x+3)(x-1) + (x-2)(5x - 4)
C = (4x + 3)[(4x -3) +x -1] + (x-2)(5x - 4)
C = (4x +3)(5x -4) + (x -2)(5x - 4)
C = (5x - 4)[4x +3 + x -2]
C = (5x -4)(5x + 1)
voila j"ai fait de mon mieux
Explications étape par étape :
