Find Your Roots

Algebra Level 1

1 x = 3 , x = ? \large \sqrt{\frac{1}{\sqrt{ x}}}=3, \ \ \ x = \ ?

81 45 0.123 1 81 \frac1{81}

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17 solutions

1 x = 3 1 x = 9 x = 1 9 x = 1 81 \color{#D61F06}{\sqrt{\frac{1}{\sqrt{x}}}=3\\ \frac{1}{\sqrt{x}}=9\\ \sqrt{x}=\frac{1}{9}\\x=\boxed{\frac{1}{81}}}

Whyyyy didnt i think of that? *facepalm

Muhd Aqmal Hakim - 5 years, 4 months ago

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I feel stupid too

Amir Hussein - 5 years, 1 month ago

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really. i too, feel stupid

Archit Choudhary - 5 years, 1 month ago

I too feel stupid....😭😭

Darshika Wijesena - 4 years, 12 months ago

Lol, I feel ya brotha!

Ronnie Blue - 5 years ago

It's not only on solution, since the root of something under the fraction bar is the same as 2 as exponent, wait forget it, I've figurer out im wrong...

Alan Harkness - 5 years ago

Very helpful wow

Zay Willis - 5 years, 4 months ago

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very helpful..

Shanmathi devaraj - 5 years, 4 months ago

Try do it without a paper :)

Henrique Nascimento - 5 years, 2 months ago

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Did it in my head because I was too lazy to get a pen and paper, even though they were right beside me. :-P

Rohit Prasad - 5 years ago

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Same. I would have gotten it right had I actually written it on some paper.

Bryan Giannone - 5 years ago

When i see the solution = "facepalm"

Felix Fernando - 5 years, 1 month ago

1 / 81 = 0.01234567901234567901234567901235 round result --> 0.0123 ;)

R3D One - 5 years, 2 months ago

Face palm i was near solution then i made my mind on getting direct solution in confusion 😥

Aminah Khan - 4 years, 11 months ago

I was so stuck on making it more complicated then it actually was

Kriz Bueno - 5 years ago

Wow its all about Understanding Math Love you Math😊

Shehzad Ahmed Shez - 4 years, 11 months ago

I tried to click on 1/81 and nothing happened. The "teaching" portion is nothing more than a link to Wikipedia. Total waste of time. Go to Kahn Academy.

Michael Sartin - 4 years, 4 months ago
Jack Rawlin
Dec 22, 2014

1 x = 3 \sqrt {\frac {1}{\sqrt {x}}} = 3

First you square both sides to get rid of one of the square roots

1 x = 3 1 x = 9 \sqrt {\frac {1}{\sqrt {x}}} = 3 \Rightarrow \frac {1}{\sqrt {x}} = 9

Since 1 = 1 \sqrt {1} = 1 we can re-write it as

1 x = 9 \sqrt {\frac {1}{x}} = 9

Squaring again gives us

1 x = 81 \frac {1}{x} = 81

Multiply both sides by x x to get rid of the x x on the bottom

1 = 81 x 1 = 81x

Divide by 81 81

x = 1 81 x = \frac {1}{81}

So the answer is 1 81 \frac {1}{81}

Great solution, thank you! This should be #1.

Michael Sena - 4 years, 11 months ago
Andrés Molina
Dec 18, 2014

Extremely logical

Anwesha Karmakar - 4 years, 6 months ago

thanks for solution

Saint Hentai - 1 year, 10 months ago

Zizo Bahnasy
Dec 20, 2014

My method took a little bit longer than a few other methods, but it is the first method that came to mind.

1 x = 3 \sqrt{\frac{1}{\sqrt{x}}} = 3

1 x = 9 {\frac{1}{\sqrt{x}}} = 9

x x = 9 x x {\frac{\sqrt{x}}{x}} = {\frac{9\sqrt{x}}{\sqrt{x}}}

x = 9 x x x \sqrt{x} = {\frac{9x\sqrt{x}}{\sqrt{x}}}

x = 9 x \sqrt{x} = 9x

x = 81 x 2 x = 81x^{2}

1 = 81 x 1 = 81x

x = 1 / 81 x = 1/81

Alicia Brown
Nov 20, 2015

A man lives at tenth floor of a block of flats he can reach to number 8 BUT hes lucky thats its raining how is it possible

Leaking roofs

Tom Hunt - 5 years, 6 months ago

got his brolly with him?

Steve Bradley - 5 years, 1 month ago

Having his brolly means he can teach the number 10 button 😁

Scott Fasciolo-Barnes - 4 years, 7 months ago
Jemrick Ramos
Dec 19, 2015

√[1/(√x )] = 3

√{1/[x^(1/2)]} = 3

√[x^(-1/2)] = 3

[x^(-1/2)]^(1/2) = 3

x^(-1/4) = 3

[x^(-1/4)]^-4 = 3^-4

x^(-4/-4) = 1/(3^4)

x = 1/81

Interesting way of finding x . . . I like it.

Briana Lightbourn - 5 years, 3 months ago
Mohammad Khaza
Jul 4, 2017

here it is:

             √ (1/√x) =3

or, {√ (1/√x)}^2 = 3^2 ......................................[whole square]

or, 1/√x = 9

or, √x= 1/9

or, (√x)^2= (1/9)^2

or, x= 1/81

Ryan Haywood
Jan 17, 2016

Tbh I just guessed...

Deepanshu Dhruw
Jan 4, 2016

Gia Hoàng Phạm
Sep 22, 2018

1 x = 3 1 x = 9 x = 1 9 x = 1 81 \sqrt{\frac{1}{\sqrt{x}}}=3 \implies \frac{1}{\sqrt{x}}=9 \implies \sqrt{x}=\frac{1}{9} \implies x=\boxed{\large{\frac{1}{81}}}

square both sides, square both sides again ... x = 1/81

As we have two square root signs in LHS we have to remove one of it to make equation simpler. So first we will square it. i.e 1/√x=9 Now as we want the value of x we will square it again. i.e 1/x=81 i.e X=1/81

Teesta Maulik
Jun 11, 2016

Substitute x x for 1 81 \frac{1}{81} and look at this method. Remember 1 1 over 1 81 \frac{1}{81} basically means 81 1 \frac{81}{1} which leads us into having 81 81 . So the root of 81 81 is 9 9 and the root of 9 9 is 3 .

√(1/√x) = 3

(1/√x) = 9

√x/x = 9

√x = 9x

x = 81x²

x/x² = 81x²/x²

x-¹ = 81

1/x = 81

1 = 81x

1/81 = x

That took longer than it should.

Otibhor Imuse
Dec 22, 2015

Square both sides to remove d square root on d LHS {√1/√x}^2=3^2....1/√x=9.....√x=1/9....x=1/81

Khang Di Nguyen
Dec 19, 2015

Errr..... Why is the answer is in bold?

duh khang. because x = y. But. we have 2 factorial to the power of a 5 to a 5 squared.

Am Kemplin - 1 month, 2 weeks ago

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