Write the following as a single logarithm. Assume all variables are positive. \( \log _{4}(5)+3 \log _{4}(y)= \) The answer format in lowercase characters is: log_base (number) Spaces in the answer are optional.

We start with the expression \[ \log_4(5) + 3\log_4(y) \] Use the power rule of logarithms: \[ 3\log_4(y)=\log_4(y^3) \] Then, apply the product rule for logarithms: \[ \log_4(5) + \log_4(y^3)=\log_4(5y^3) \] The final answer is: \[ \text{log}_4(5y^3) \]