Answer
$\color{blue}{1}$
Work Step by Step
RECALL:
(1) $(a+b)(a-b) = a^2-b^2$
(2) For $a\gt0$, $(\sqrt{a})^2 = a$
Use rule (1) above by to obtain:
$=2^2 - (\sqrt{3})^2
\\=4-(\sqrt3)^2$
Use rule (2) above to obtain:
$\\=4-3
\\=\color{blue}{1}$
