Réponses

2013-11-24T19:43:53+01:00
5x*2y*2xy
=20x²y²

9a+8b-(15a-4b)
=9a+8b-15a+4b
=-6a+12b

5x*2y-(2y*7y+xy)
=10xy-14y²+xy
=11xy-14y²

5a*(ab-b)-a²
=5a²b-5ab-a²