Respostas

2013-07-29T18:03:59-03:00
10y-5-5y=6y-6-20
5y-6y=5-26
-y=-21(-1)
y=21

2013-07-29T18:05:23-03:00
10y-5-5y=-6y-6+20
10y-5y+6y=20+5
11y=25
y=0.44