Answer
$52-14\sqrt 3$
Work Step by Step
Step 1: The expression to be used here is, $(a-b)^{2}=a^{2}-2ab + b^{2}$
Step 2: Accordingly, the expression in the question becomes $(\sqrt 3-7)^{2}= (\sqrt 3)^{2}- 2(\sqrt 3)(7) + 7^{2}$
Step 3: Simplifying, $(\sqrt 3)^{2}- 2(\sqrt 3)(7) + 7^{2}$= $3-14\sqrt 3+49= 52-14\sqrt 3$
