Question

ai giúp mình được không ạ

 

Answer 1

a.

\(=\sqrt{\left(2x^2\right)^2}.\sqrt{\left(y-2\right)^2}=2x^2.\left(2-y\right)\) 

b.

\(=\dfrac{\sqrt{x+3}-1}{x+3-1}=\dfrac{\left(\sqrt{x+3}-1\right)\left(\sqrt{x+3}+1\right)}{\left(x+3-1\right)\left(\sqrt{x+3}+1\right)}=\dfrac{1}{\sqrt{x+3}+1}\)

c.

\(=\dfrac{\sqrt{x}\left(1+\sqrt{xy}\right)-\sqrt{y}\left(1+\sqrt{xy}\right)}{xy-1}=\dfrac{\left(\sqrt{x}-\sqrt{y}\right)\left(1+\sqrt{xy}\right)}{\left(\sqrt{xy}-1\right)\left(\sqrt{xy}+1\right)}=\dfrac{\sqrt{x}-\sqrt{y}}{\sqrt{xy}-1}\)

d.

\(=\dfrac{x-\sqrt{5}}{x\left(x+\sqrt{2}\right)-\sqrt{5}\left(x+\sqrt{2}\right)}=\dfrac{x-\sqrt{5}}{\left(x+\sqrt{2}\right)\left(x-\sqrt{5}\right)}=\dfrac{1}{x+\sqrt{2}}\)