Question

what is the square root of 20x over X^3

Answer 1

\[\sqrt{(\frac{20x}{x^3})}\]
This?

Answer 2

YEEEESSSSSSSSSSSSSSSSSSSSSS

Answer 3

Well, work with the inside of the square root first. How can you simplify \(\frac{20x}{x^3}\)

Answer 4

you square out the 20 and get 2 square root 5

Answer 5

or \[2\sqrt{5}\]

Answer 6

I said to ignore the square root first. Just deal with inside the square root for a second.

Answer 7

\[\frac{20x}{x^3}\] Can be simplified to what?

Answer 8

you would multiply the numerator by \[ \times ^{3}\] and get \[20x ^{4}\]

Answer 9

No.

\[\frac{20x}{x^3} = \frac{20*x}{x*x*x}\]
We can cancel one x from top and bottom.
\[=\frac{20}{x^2}\]

Answer 10

ohhhh and then I would get \[\sqrt{20} \over \sqrt{x ^{?}}\]

Answer 11

Yep

Answer 12

then get \[2\sqrt{5} \over x ^{2}\]

Answer 13

wait

Answer 14

its \[2\sqrt{5} \over \sqrt{x ^{2}}\]

Answer 15

then get \[2x ^{2} \sqrt{5} \]

Answer 16

please tell me if that is right!

Answer 17

No. \(\sqrt{x^2} = |x|\)

Answer 18

So you have \[\frac{2\sqrt{5}}{\sqrt{x^2}} = \frac{2\sqrt{5}}{|x|} \]

Answer 19

I think you should review fractions because you keep moving the things in the denominator up to the numerator.

Answer 20

You can't really do that.

Answer 21

\[a*b \ne \frac{a}{b} \] Unless a=1 and b=1

Answer 22

my teacher taught us that way. She said that youcan not have a square root in the demoninator

Answer 23

No, you can. Often people prefer to have only square roots in the numerator, but in that case you must multiply the top and bottom by an extra factor of the square root.

\[\frac{a}{\sqrt{b}} \]
\[= \frac{a}{\sqrt{b}} *1 \]
\[= \frac{a}{\sqrt{b}} *\frac{\sqrt{b}}{\sqrt{b}} \]
\[= \frac{a\sqrt{b}}{\sqrt{b^2}} \]
\[= \frac{a\sqrt{b}}{b}\]

Answer 24

yea that looks like the way she said it

Answer 25

Does that make sense? You cannot just move the square root in the denominator up to the numerator. Otherwise you get bad values.

\[\frac{a}{\sqrt{b}} = a\sqrt{b} \implies \frac{1}{\sqrt{b}} = \sqrt{b} \implies 1 = \sqrt{b^2} \implies b = 1\]

So the only thing you can bring directly from the numerator to the denominator is a 1.

Answer 26

Or the denominator to the numerator.

Answer 27

ok

Answer 28

Are youa teacher?

Answer 29

I'm not a teacher.. Just a person who's done a lot of math and tutor people.


Review your simplification rules for fractions:

http://www.khanacademy.org/video/simplifying-rational-expressions-1?playlist=Algebra%20I%20Worked%20Examples

Answer 30

THANK YOU GOD BLESS YOU!!!! GOODNIGHT