\(A=\sqrt{\dfrac{4+\sqrt{7}}{2}}-\dfrac{1}{2}=\sqrt{\dfrac{8+2\sqrt{7}}{4}}-\dfrac{1}{2}\)
\(=\dfrac{\sqrt{7}+1}{2}-\dfrac{1}{2}=\dfrac{\sqrt{7}}{2}\)
\(B=3+\dfrac{\sqrt{3}}{\sqrt{2}+\sqrt{3}}=3+\sqrt{3}\left(\sqrt{3}-\sqrt{2}\right)\)
\(=3+3-\sqrt{6}=6-\sqrt{6}\)