bài 1 tính
a)\(\left(\dfrac{\sqrt{14}-\sqrt{7}}{2-\sqrt{8}}+\dfrac{1}{\sqrt{7}-\sqrt{5}}\right):\sqrt{5}\)
bài 2 A = \(\left(\dfrac{X+3}{\sqrt{X}+1}-\sqrt{X}\right):\left(\dfrac{9-\sqrt{X}}{x-1}-\dfrac{\sqrt{x}}{\sqrt{x}+1}\right)\)
a)tìm Amin
b)tìm x nguyên đẻ a nguyên
c) tìm x dể a nguyên
Câu 1:
\(=\left(\dfrac{\sqrt{7}\left(\sqrt{2}-1\right)}{2\left(1-\sqrt{2}\right)}+\dfrac{\sqrt{7}+\sqrt{5}}{2}\right):\sqrt{5}\)
\(=\dfrac{-\sqrt{7}+\sqrt{7}+\sqrt{5}}{2}\cdot\dfrac{1}{\sqrt{5}}=\dfrac{1}{2}\)