c: \(\left(\sqrt{\dfrac{9}{2}}+\sqrt{\dfrac{1}{2}}+\sqrt{2}\right)\cdot\sqrt{2}\)
\(=\sqrt{\dfrac{9}{2}\cdot2}+\sqrt{\dfrac{1}{2}\cdot2}+\sqrt{2\cdot2}\)
=3+1+2
=6
d: Ta có: \(\left(1+\sqrt{3}-\sqrt{5}\right)\left(1+\sqrt{3}+\sqrt{5}\right)\)
\(=4+2\sqrt{3}-5\)
\(=2\sqrt{3}-1\)