Respostas

2013-11-26T11:32:48-02:00
x-1/x+1 -2/5 = 2x/5x+5, tira o mmc ( que no caso será 5x+5 )
={[(5)(x-1)]-[(x+1)(2)]}/(5x+5)= 2x/(5x+5)=
=5x-5-2x-2=2x 
= 3x-7= 2x
=  x = 7

1 5 1