Question

Rút gọn các biểu thức

a,\(\dfrac{x-\sqrt{xy}}{\sqrt{x}-\sqrt{y}}\)

b,\(\left(a-b\right)\sqrt{\dfrac{a^2b^2}{\left(a-b\right)^2}}\)

c,\(\dfrac{a-\sqrt{3a}+3}{a\sqrt{a}+3\sqrt{3}}\)

Answer 1

@Nhã Doanh

Answer 2

a) \(\dfrac{x-\sqrt{xy}}{\sqrt{x}-\sqrt{y}}=\dfrac{\sqrt{x}.\left(\sqrt{x}-\sqrt{y}\right)}{\sqrt{x}-\sqrt{y}}=\sqrt{x}\)

Answer 3

a: \(=\dfrac{\sqrt{x}\left(\sqrt{x}-\sqrt{y}\right)}{\sqrt{x}-\sqrt{y}}=\sqrt{x}\)

b: \(=\left(a-b\right)\cdot\dfrac{\left|ab\right|}{\left|a-b\right|}=\pm\left|ab\right|\)

c: \(=\dfrac{1}{\sqrt{a}+\sqrt{3}}\)