We are given two pentagons.
Firstly, we need a dilation and then translation to get the first pentagon to land perfectly on top of the second pentagon.
The scale factor for dilation is given by
[tex]s=\frac{8}{10}=0.80[/tex]Now we can find the missing length of the side x
[tex]\begin{gathered} \frac{x}{12}=\frac{8}{10} \\ x=12\cdot\frac{8}{10} \\ x=9.6 \end{gathered}[/tex]So, the missing side x is 9.6
Therefore, first, perform a dilation by a scale factor of 0.80 and then perform a horizontal translation to the right.