jmc

It is much easier to find $10110_2÷10_2$ and then multiply by $10100_2$ than it is to do the calculations in the original order. For $10110_2÷10_2$, since the last digit of $10110_2$ is a 0, we can simply take it off to get $1011_2$. This is similar to base 10, where $10110_{10}÷10_{10}=1011_{10}$. In base 2, each place represents a power of 2, and since we're dividing by 2, each place goes down by a power 2, so each digit shifts to the right. Now we find the product of $1011_2$ and $10100_2$. \begin{array}{@{}c@{\;}c@{}c@{}c@{}c@{}c@{}c@{}c@{}c} & & &1 &0 & 1 & 1_2 & & \\ & & & \times & 1& 0 & 1& 0 & 0_2 \\ \cline{1-9}& & &1 &0 &1 &1 & & \\ & & & & & &0 & & \\ & 1 &\stackrel{1}{0}&1 &1 &0 &0 &\downarrow &\downarrow \\ \cline{1-9} &1 &1 &0 &1 &1 &1 &0 &0_2 \\ \end{array}The answer is $\boxed{11011100_2}$.