We have the following
[tex]\begin{gathered} \log a=4 \\ \log b=-16 \\ \log c=19 \\ \log (\frac{a^2\cdot c}{\sqrt[]{b}}) \end{gathered}[/tex]Let's find a, b and c in order to solve the problem
a.
[tex]\begin{gathered} \log a=4 \\ a=10^4=10000 \end{gathered}[/tex]a = 10,000
b.
[tex]\begin{gathered} \log b=-16 \\ b=10^{-16}=\frac{1}{10^{16}} \end{gathered}[/tex]b=1.0E-16
c.
[tex]\begin{gathered} \log c=19 \\ c=10^{19} \end{gathered}[/tex]c=1.0E19
Thus, the value of log [ a^2c/sqrt(c) ] is :
replace:
[tex]\log (\frac{a^2\cdot c}{\sqrt[]{b}})=\log _{10}\mleft(\frac{\left(10^4\right)^2\cdot\:10^{19}}{\sqrt{10^{-16}}}\mright)[/tex]simplify:
[tex]\begin{gathered} \frac{\left(10^4\right)^2\cdot\:10^{19}}{\sqrt{10^{-16}}}=\frac{10^8\cdot10^{19}}{10^{-8}}=10^8\cdot10^8\cdot10^{19}=10^{8+8+19}=10^{35} \\ \Rightarrow\log 10^{35}=35 \end{gathered}[/tex]Therefore, the answer is 35