Question

giúp e bài 1 với ạ,e cảm ơn

Answer 1

c: Ta có: \(\sqrt{7-4\sqrt{3}}+\sqrt{7+4\sqrt{3}}\)

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

=4

d: Ta có: \(\dfrac{\sqrt{a}-\sqrt{b}}{\sqrt{a}+\sqrt{b}}+\dfrac{\sqrt{a}+\sqrt{b}}{\sqrt{a}-\sqrt{b}}\)

\(=\dfrac{a-2\sqrt{ab}+b+a+2\sqrt{ab}+b}{a-b}\)

\(=\dfrac{2a+2b}{a-b}\)