\begin{flalign*}
z&=\frac{\splitfrac{ab+cd+ef+gh+ij}{+kl+mn+op+qr}}{y}\\
z&=\frac{\splitdfrac{ab+cd+ef+gh+ij}{+kl+mn+op+qr}}{y}
\end{flalign*}
It can be seen from the figure below there is an additional term of 1 and 0 in the second line of split equation. I wonder why ? How can i rectify it ?


\documentclassand ending with\end{document}. – Bobyandbob Jun 14 '17 at 22:27flalign*does the same asalign*, with your input. – egreg Jun 14 '17 at 22:32mathtoolsin thearticleclass). – Werner Jun 14 '17 at 22:42