Bài 3:
a: Ta có: \(A=\left(\sqrt{12}+\sqrt{\left(-2\right)^2}-\sqrt{27}\right)\left(2+\sqrt{3}\right)\)
\(=\left(2-\sqrt{3}\right)\left(2+\sqrt{3}\right)\)
=4-3
=1
b: Ta có: \(B=5\sqrt{3}+2-\sqrt{7-4\sqrt{3}}\)
\(=5\sqrt{3}+2-2+\sqrt{3}\)
\(=6\sqrt{3}\)