Question

giúp mình câu này với ạ

Answer 1

\(=\dfrac{4\left(\sqrt{7}+\sqrt{5}\right)}{7-5}+\dfrac{8\left(\sqrt{3}+\sqrt{7}\right)}{3-7}=\dfrac{4\left(\sqrt{7}+\sqrt{5}\right)}{2}+\dfrac{8\left(\sqrt{3}+\sqrt{7}\right)}{-4}=2\left(\sqrt{7}+\sqrt{5}\right)-2\left(\sqrt{3}+\sqrt{7}\right)=2\sqrt{7}+2\sqrt{5}-2\sqrt{3}-2\sqrt{7}=2\sqrt{5}-2\sqrt{3}\)

Answer 2

\(=2\left(\sqrt{7}+\sqrt{5}\right)-2\left(\sqrt{7}+\sqrt{3}\right)\)

\(=2\sqrt{7}+2\sqrt{5}-2\sqrt{7}-2\sqrt{3}\)

\(=2\sqrt{5}-2\sqrt{3}\)