Developpe et reduis : x est la lettre A=(4x-1)(3x+5)-(x-7) B=(x+5)(2x-5)-(3x au carré-7x+5) MERCI

Bonsoir,

A=(4x-1)(3x+5)-(x-7) 
A = 12x² + 20x - 3x - 5 - x + 7
A = 12x² + 20x - 3x - x - 5 + 7
A = 12x² + 16x + 2

B=(x+5)(2x-5)-(3x²-7x+5) 
B = 2x² - 5x + 10x - 25 - 3x² + 7x - 5
B = 2x² - 3x² - 5x + 10x + 7x - 25 - 5
B = - x² + 12x - 30

bonjour

A=(4x-1)(3x+5)-(x-7)
= 12x²+20x-3x-5-x+7
= 12x²+16x+2

B=(x+5)(2x-5)-(3x²-7x+5)
b = 2x²-5x+10x-25-3x²+7x-5
b =  -x² +12x -30