Given:
[tex]\frac{7}{2}mm\ast\frac{14}{5}mm[/tex]Let's multiply the fractions.
To multiply the fractions, multiply the numertaors together, also multiply the denominators together.
Thus, we have:
[tex]\begin{gathered} \frac{7}{2}\ast\frac{14}{5} \\ \\ \frac{7\ast14}{2\ast5} \end{gathered}[/tex]Solving further:
cancel the common factor of 2:
[tex]\frac{7\ast7}{1\ast5}=\frac{49}{5}[/tex][tex]undefined[/tex]