ANSWER:
[tex]2p+5=21[/tex]
STEP-BY-STEP EXPLANATION:
Let p be the figure of the pentagon.
We can establish the following equation:
[tex]\begin{gathered} 2p+5=10+10+1 \\ 2p+5=21 \end{gathered}[/tex]
Therefore, the correct answer is the 4th option a) 2p + 5 = 21
