Question 1

$\begin{array}{c}\begin{array}{ccc}& & \begin{array}{c}\begin{array}{cc}\mathrm{<mn>3</mn>}& \mathrm{<mn>4</mn>}\end{array}\end{array}\\ \underline{}& \underline{-}& \underline{\begin{array}{c}\begin{array}{cc}\mathrm{<mn>2</mn>}& \end{array}\end{array}}\\ \underline{\begin{array}{}\\ \end{array}}& \underline{-}& \underline{\begin{array}{cc}\mathrm{<mn>1</mn>}& \mathrm{<mn>4</mn>}\\ \mathrm{<mn>1</mn>}& \mathrm{<mn>4</mn>}\end{array}}\\ & & \begin{array}{cc}& 0\end{array}\end{array}\end{array}\begin{array}{c}\overline{)\mathrm{<mn>2</mn>}}\\ \begin{array}{cc}\mathrm{<mn>1</mn>}& \mathrm{<mn>7</mn>}\end{array}\end{array}$