Réponses

2014-01-11T11:43:33+01:00
 x² -2x+1+5(x-1)
=(x-1)²+5(x-1)
=(x-1)(x-1)+5(x-1)
=(x-1)(x-1+5)
=(x-1)(x+4)       

3x-3+x-1
=3(x-1)+(x-1)
=(x-1)(3+1)
=4(x-1)

4x² -8x+4+( x² -1)
=4(x²-2x+1)+(x-1)(x-1)
=4(x-1)²+(x-1)(x-1)
=(x-1)(4x-4+x-1)
=(x-1)(5x-5)
=5(x-1)(x-1)