Respostas

2014-03-24T21:02:24-03:00
2014-03-24T21:10:34-03:00
 \left \{ {{g+p = 80} \atop {g = 3p}} \right. 

 \left \{ {{g+p = 80} \atop {g-3p = 0}} \right.
(multiplicando por -1 e somando, resolve-se:)
+ \left \{ {{-g-p = -80} \atop {g-3p = 0}} \right.
portanto: -4p = -80
4p = 80
p = 80/4
p = 20
Logo: g+p = 80
g+20 = 80
g = 80-20
g = 60
Há 20 porcos e 60 galinhas