published on: 2013-10-24 18:55:01
ccoleciona-dor.tumblr.com/post/64972930005/
ccoleciona-dor.tumblr.com/post/64972940116/
ccoleciona-dor.tumblr.com/post/64973231891/
▲= b² - 4.a.c
ccoleciona-dor.tumblr.com/post/64974160145/
ccoleciona-dor.tumblr.com/post/65003031001/