Respostas

2013-07-04T21:00:59-03:00
2bx(1-a) + 2x(a-b-c)-2x(a-c) 

2bx-2bxa+2xa-2xb-2xc-2xa+2xc

2bx-2bxa-2xb = -2bxa

confere?
2 3 2
2013-07-04T21:50:05-03:00
2bx(1-a) + 2x(a-b-c)-2x(a-c) 
2bx-2abx+2ax-2bx-2cx-2ax+2cx
-2abx