Réponses

2013-11-07T21:24:12+01:00
2(x-7b)+3(x-7b)
(x-7b)(2+3)
(x-7b)5
4(a+3)-5y(a+3)
(a+3)(4-5y)
(4x-7)²-3x(4x-7)
(4x-7)(4x-7-3x)
(4x-7)(x-7)
2013-11-07T21:46:27+01:00
2(x-7b) + 3 (x-7b)
=2x-14b+3x-21b
=5x-35b
factorisation: (x-7b)+(2+3)=5(x-7b)

4(a+3)-5y(a+3)
=4a+12-5ay-15y
factorisation: (a+3)(4-5y)

(4x-7)² - 3x(4x-7)
=16x²-56y+49-12x²+21x
=4x²-56y+21x+49 
factorisation: (4x-7)(4x-7-3x)=(4x-7)(x-7)