Question 1: Calculate: \( M = \left( {2\frac{1}{3} + 3,5} \right):\left( { – 4\frac{1}{6} + 3\frac{ 1}{7}} \right) + 7.5\)

\(\begin{array}{l} M = \left( {2\frac{1}{3} + 3,5} \right):\left( { – 4\frac{1}{6} + 3 \frac{1}{7}} \right) + 7,5\\ \begin{array}{*{20}{c}} \begin{array}{l} \\ \end{array}&{ = \left( {\frac{7}{3} + \frac{7}{2}} \right):\left( {\frac{{ – 25}}{6} + \frac{{22}}{ 7}} \right) + 7,5}\\ {}&{ = \left( {\frac{{14}}{6} + \frac{{21}}{6}} \right):\left ( {\frac{{ – 175}}{{42}} + \frac{{132}}{{42}}} \right) + 7,5}\\ {}&{ = \frac{{35} }{6}:\frac{{ – 43}}{{42}} + 7,5}\\ {}&{ = \frac{{35}}{6}.\frac{{ – 42}}{ {43}} + \frac{{15}}{2}}\\ {}&{ = \frac{{ – 245}}{{43}} + \frac{{15}}{2}}\\ {}&{ = \frac{{ – 490}}{{86}} + \frac{{645}}{{86}}}\\ {}&{ = \frac{{155}}{{86} } = 1\frac{{69}}{{86}}} \end{array} \end{array}\)