Question

[phước]

đưa thừa số vào trong dấu căn

a) \(\frac{x-y}{x}\times\sqrt{\frac{x}{x-y}}\)           (x>0: x>y)

b) \(\frac{x+y}{x-y}\times\sqrt{\frac{x-y}{x+y}}\)      (x>0: x.y)

c) \(\frac{^{x^2}}{x-5}\times\sqrt{\frac{x-5}{3x}}\)     (x>5)

d) \(-2\sqrt{-a}\) 

Answer 1

[Tuyển Trần Thị]

a, \(\sqrt{\frac{\left(x-y\right)^2}{x^2}\cdot\frac{x}{x-y}}=\) \(\frac{x-y}{x}\)

b. \(\sqrt{\frac{\left(x+y\right)^2}{\left(x-y\right)^2}\cdot\frac{x-y}{x+y}}=\sqrt{\frac{x+y}{x-y}}\)

c.\(\sqrt{\frac{x^4}{\left(x-5\right)^2}\cdot\frac{x-5}{3x}}=\sqrt{\frac{x^3}{3\left(x-5\right)}}\)

\(-2\sqrt{-a}=\sqrt{\left(-2\right)^2\cdot-a}=\sqrt{-4a}\)