Answer
$7+9\sqrt7$
Work Step by Step
The distributive property states that for any real numbers $a, b, $ and $c$,
$a(b+c) =a\cdot b+a \cdot c$
Thus, apply the distributive property to the given problem to find:
$=\sqrt7\cdot 9 + \sqrt7 \cdot \sqrt{7}
\\=9\sqrt{7}+7$
