\[log_3(log_5 x)=7\]
we can repeatedly raise the base to the power of both sides,remebering that \[a^{log_a y}=y\]
.First raise 3 to the power of both sides.
\[3^{log_3(log_5 x)}=3^7\]
\[log_5 x=3^7\]
Now raise 5 to the power of both sides.
\[5^{log_5 y}=5^{3^7}\]
\[5^{log_5 y}=5^{3^7}\]
\[y=5^{3^7}\]