Answer
$x\log_{2}5+\log_{2}8=\log_{2}(8\cdot5^{x})$
Work Step by Step
$x\log_{2}5+\log_{2}8$
Take the $x$ multiplying in front of $\log_{2}5$ inside as an exponent:
$x\log_{2}5+\log_{2}8=\log_{2}5^{x}+\log_{2}8=...$
Combine $\log_{2}5^{x}+\log_{2}8$ as the $\log$ of a product:
$...=\log_{2}(8\cdot5^{x})$