Respostas

2013-09-23T17:52:44-03:00
Veja:
x+x/4=80
(4x+x)/4=320/4
4x+x=320
5x=320
x=320/5
x=64.
2013-09-23T17:58:44-03:00
X+x/4=80
4x+x=20
5x=20
x=20/5
x=4