Oplossing week 9

$\begin{array}{l} a.\,\,\,\left( {\begin{array}{*{20}{c}} 7\\ 2 \end{array}} \right) \cdot \left( {\begin{array}{*{20}{c}} 5\\ 2 \end{array}} \right) = 210\\ b.\,\,\,7 \cdot \left( {\begin{array}{*{20}{c}} 5\\ 2 \end{array}} \right) + \left( {\begin{array}{*{20}{c}} 7\\ 2 \end{array}} \right) \cdot 5 = 175 \end{array}$