Answer
$5$;
$6\sqrt3$
Work Step by Step
Simplifying the radical gives
$\sqrt{3} + \sqrt{25\cdot 3}
\\=\sqrt{3} + \sqrt{5^2 \cdot 3}
\\=\sqrt{3} + \sqrt{5^2} \cdot \sqrt{3}
\\=\sqrt{3} + \underline{5}\sqrt{3}.$
Use the rule $ac+bc=(a+b)c$ to obtain
$=(1+5)\sqrt{3}
\\=\underline{6\sqrt{3}}.$
Thus, the missing expressions are: $5$ and $6\sqrt{3}.$
