Answer:
[tex]\displaystyle z = 4\, \log_{10} \left(\frac{32}{5}\right)[/tex].
Step-by-step explanation:
Multiply both sides by [tex](1/5)[/tex] and simplify:
[tex]\displaystyle \frac{1}{5} \times 5\, (10)^{z/4} = \frac{1}{5} \times 32[/tex].
[tex]\displaystyle (10)^{z/4} = \frac{32}{5}[/tex].
Take the base-[tex]10[/tex] logarithm of both sides:
[tex]\displaystyle \log_{10}\left(10^{z/4}\right) = \log_{10} \left(\frac{32}{5}\right)[/tex].
[tex]\displaystyle \frac{z}{4} = \log_{10}\left(\frac{32}{5}\right)[/tex].
[tex]\displaystyle z = \log_{10}\left(\frac{32}{5}\right)[/tex].