Answer
$-71$
Work Step by Step
RECALL:
$(a-b)(a+b)=a^2-b^2$
Use the formula above with $a=2$ and $b=5\sqrt{3}$ to obtain:
$=2^2- (5\sqrt{3})^2
\\=4-5^2(3)
\\=4-25(3)
\\=4-75
\\=-71$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.