Question

RÚT GỌN BIỂU THỨC SAU;

a, \(\frac{\sqrt{a}-a}{\sqrt{a}-1}\)          c,\(\frac{a-b+2\sqrt{ab}}{\sqrt{a}+\sqrt{b}}\)     e,\(\frac{x-y+3\sqrt{x}+3\sqrt{y}}{\sqrt{x}-\sqrt{y}+3}\)

b, \(\frac{a-b}{\sqrt{a}-\sqrt{b}}\)     d,\(\frac{x\sqrt{x}-y\sqrt{y}+x\sqrt{y}-y\sqrt{x}}{x+y+2\sqrt{xy}}\)

Answer 1

các bn trả lời giúp mk câu hỏi đó vs 

Answer 2

a/ \(\frac{\sqrt{a}-\left(\sqrt{a}\right)^2}{\sqrt{a}-1}\)

=\(\frac{\sqrt{a}\left(1-\sqrt{a}\right)}{\sqrt{a}-1}\)

=\(\frac{-\sqrt{a}\left(1-\sqrt{a}\right)}{1-\sqrt{a}}\)

=\(-\sqrt{a}\)

Answer 3

b/

=\(\frac{\left(\sqrt{a}\right)^2-\left(\sqrt{b}\right)^2}{\sqrt{a}-\sqrt{b}}\)

=\(\frac{\left(\sqrt{a}+\sqrt{b}\right)\cdot\left(\sqrt{a}-\sqrt{b}\right)}{\sqrt{a}-\sqrt{b}}\)

=\(\sqrt{a}+\sqrt{b}\)