nhờ giúp nhưng có chữ '' đm '' là x100 công lực :))))

gánh còng não :v

\(\left(\dfrac{\sqrt{y}}{x+\sqrt{y}}+\dfrac{\sqrt{y}}{x-\sqrt{xy}}\right):\dfrac{2\sqrt{xy}}{xy}=\left(\dfrac{\sqrt{y}}{x+\sqrt{y}}+\dfrac{\sqrt{y}}{\sqrt{x}\left(\sqrt{x}-\sqrt{y}\right)}\right):\dfrac{2}{\sqrt{xy}}=\dfrac{\sqrt{xy}\left(\sqrt{x}-\sqrt{y}\right)+\sqrt{x}\left(x+\sqrt{y}\right)}{\sqrt{x}\left(x+\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}\right)}:\dfrac{2}{\sqrt{xy}}=\dfrac{x\sqrt{y}-y\sqrt{x}+x\sqrt{x}+\sqrt{xy}}{\sqrt{x}\left(x+\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}\right)}:\dfrac{2}{\sqrt{xy}}=\dfrac{\sqrt{x}\left(\sqrt{xy}-y+x+\sqrt{y}\right)}{\sqrt{x}\left(x+\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}\right)}:\dfrac{2}{\sqrt{xy}}=\dfrac{\sqrt{y}\left(\sqrt{x}-\sqrt{y}\right)+\left(x+\sqrt{y}\right)}{\left(x +\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}\right)}:\dfrac{2}{\sqrt{xy}}\) mình làm đc đó thôi ( mỏi tay :v )

a , S_AB = 45 . 3 = 135 km

Huong will be twelve on Saturday November 20^th

thật tội nghiệp :'((

tự ái, chúa ơi, tôi yêu nó!

?????

1716 : y = 12 . 13 

⇔ \(\dfrac{1716}{y}\) = 156 

⇔ 1716 = 156.y

⇔ y = 11 

y . \(\dfrac{2}{3}+y.\dfrac{1}{6}=\dfrac{10}{3}\)

⇔ \(\dfrac{5}{6}x=\dfrac{10}{3}\)

⇔ x = 4