published on: 2013-10-24 18:54:12
ccoleciona-dor.tumblr.com/post/64972921246/
ccoleciona-dor.tumblr.com/post/64972930005/
ccoleciona-dor.tumblr.com/post/64973000517/
ccoleciona-dor.tumblr.com/post/64973231891/
▲= b² - 4.a.c
ccoleciona-dor.tumblr.com/post/64974160145/