A equao da recta tangente  curva $x^2y+3xy^3-x=3$ no ponto $(1,1)$ :
\begin{enumerate}pyB
subst = [r"$y=\frac{7}{5}-\frac{2}{5}x$",r"$y=1-\frac{2}{5}x$",r"$y=-\frac{2}{5}(x-1)$",r"$y=-\frac{2}{5}x$"]
unsorted = shuffle( subst )
certa[0] = unsorted[0]
opts = unsorted[1]
for i in opts:
    emit( "\n\\item ", i)
pyE
\end{enumerate}