Pls help me with this photo I can’t seem to understand

Notice that:
[tex]\begin{gathered} 36=6^2, \\ 64=8^2, \\ 225=15^2, \\ 169=13^2\text{.} \end{gathered}[/tex]Therefore:
[tex]\begin{gathered} \sqrt[]{36}=6, \\ \sqrt[]{64}=8, \\ \sqrt[]{225}=15, \\ \sqrt[]{169}=13. \end{gathered}[/tex]Answer:
[tex]\begin{gathered} \sqrt[]{36}=6, \\ \sqrt[]{64}=8, \\ \sqrt[]{225}=15, \\ \sqrt[]{169}=13. \end{gathered}[/tex]