Question

Trục căn thức ở mẫu với giả thiết $a, b, x, y$ là những số dương:

a) $\dfrac{a}{\sqrt{a}}$;

b) $\dfrac{a}{\sqrt{a b}}$;

c) $\dfrac{x}{\sqrt{3 x^{3}}}$;

d) $\dfrac{4 y^{2}}{\sqrt{2 y^{5}}}$.

Answer 1

a, \(\frac{a}{\sqrt{a}}=\sqrt{a}\)

b, \(\frac{a}{\sqrt{ab}}=\frac{\sqrt{a}}{\sqrt{b}}=\frac{\sqrt{ab}}{b}\)

c, \(\frac{x}{\sqrt{3x^3}}=\frac{x}{x\sqrt{3x}}=\frac{1}{\sqrt{3x}}=\frac{\sqrt{3x}}{3x}\)

d, \(\frac{4y^2}{\sqrt{2y^5}}=\frac{4y^2}{y^2\sqrt{2y}}=\frac{4}{\sqrt{2y}}=\frac{4\sqrt{2y}}{2y}=\frac{2\sqrt{2y}}{y}\)

Answer 2

a)\(\dfrac{a}{\sqrt{a}}=\dfrac{a\sqrt{a}}{a}=\sqrt{a}\)                b) \(\dfrac{a}{\sqrt{ab}}=\dfrac{a\sqrt{ab}}{\left(\sqrt{ab}\right)^2}=\dfrac{a\sqrt{ab}}{ab}=\dfrac{\sqrt{ab}}{b}\)                                              c) \(\dfrac{x}{\sqrt{3x^3}}=\dfrac{x\sqrt{3x}}{\sqrt{3x^3.\sqrt{3x}}}=\dfrac{x\sqrt{3x}}{\left(\sqrt{3x^2}\right)^2}=\dfrac{x\sqrt{3x}}{\left(3x^2\right)^2}=\dfrac{x\sqrt{3x}}{3x^2}=\dfrac{\sqrt{3x}}{3x}\)    

Answer 3

a, căn a 

b, căn ab/b

c, căn 3x/3x

d, 2 căn 2y/y

 

Answer 4

a) căn a

b) căn ab/b

c) căn 3x/3x

d) 2 căn 2y/y

Answer 5

a) √a

b) √ab /b 

c) √3x³ /3x²

d) 2√2y⁵ / y³

 

Answer 6

a) √a

b) √ab/b

c) √3x/3x

d) 2√2y/y

Answer 7

a. \(\sqrt{a}\)

b. \(\dfrac{\sqrt{ab}}{b}\)

c. \(\dfrac{\sqrt{3x}}{3x}\)

d. \(\dfrac{2\sqrt{2y}}{y}\)

Answer 8

a)can a

b) can ab/b

c) can 3x/3x

d) 2 can2y/y