\(\left(\sqrt{\dfrac{9}{2}}+\sqrt{\dfrac{1}{2}}-\sqrt{2}\right).\sqrt{2}=\sqrt{\dfrac{9}{2}}.\sqrt{2}+\sqrt{\dfrac{1}{2}}.\sqrt{2}-\sqrt{2}.\sqrt{2}=\sqrt{\dfrac{9}{2}.2}+\sqrt{\dfrac{1}{2}.2}-\sqrt{2.2}=\sqrt{9}+\sqrt{1}-\sqrt{4}=3+1-2=2\)
\(\left(\sqrt{\dfrac{9}{2}}+\sqrt{\dfrac{1}{2}}-\sqrt{2}\right).\sqrt{2}=\sqrt{\dfrac{9}{2}}.\sqrt{2}+\sqrt{\dfrac{1}{2}}.\sqrt{2}-\sqrt{2}.\sqrt{2}=\sqrt{9}+\sqrt{1}-4=3+1-4=0\)