So many 5's

Algebra Level 2

What is the fifth root of 5 5 5 5^{5^{5}} ?

5 5 3 5^{5^{3}} 5 5 2 5^{5^{2}} 5 5 4 5^{5^{4}} 5 5 5^{5}

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

9 solutions

Trevor B.
Jun 15, 2014

The fifth root of 5 5 5 5^{5^5} is equal to 5 5 5 × 1 5 = 5 5 4 5^{5^5\times\frac{1}{5}}=\boxed{5^{5^4}}

why? lets take a=5^{5}. so it becomes a^{5}. Its fifth root will be a = 5^{5}.

Prithwish Bose - 6 years, 12 months ago

Log in to reply

Here it is not {5^5}^5 It is 5^{5^5}

Suman Bhattacharjee - 6 years, 12 months ago

Log in to reply

how do u know it is in which form?

Ashish Patel - 6 years, 11 months ago

that what I did it :(

Brahim Charafi - 6 years, 10 months ago

Or 5^5^5 = 5^25 5^25^1/5 = 5^5 ?????

Hatim Zaghloul - 6 years, 12 months ago

Log in to reply

Precisely. You indicated the error that most people namely. Namely,

5 5 5 5 25 5^{5 ^5} \neq 5^{25}

In fact, we have

5 5 5 = 5 3125 5^{5^5} = 5^{3125}

Hence, the fifth root is 5 625 5^{625} .

Calvin Lin Staff - 6 years, 12 months ago

Log in to reply

Thank you.

Hatim Zaghloul - 6 years, 12 months ago

dude thats 5 th root of

Varun Raj - 6 years, 11 months ago

yes i did like this

Rishabh Jain - 6 years, 12 months ago

this answer is good...to understand ...(Y)

Salman Munir - 6 years, 11 months ago

totally agree wd u...

Rian Malik - 6 years, 11 months ago

5^5^5 okay? now what is 5^5 ? its= 5^4 * 5 = 625 * 5 so 5^5^5 = 5^ (625 * 5) fifth root is obvious 5^625 = 5^5^4

By mistake you are confused it with 5^5^2 = 5^25

Bhavik Knight - 6 years, 11 months ago

I think it would need to be in brackets - (5^5)^5

Barbora Dršková - 6 years, 11 months ago

Oh, now I get it, I misread the question.

Adrian Hansen - 6 years, 11 months ago

Really this look easy but get trick easily..

Chivacalo SK - 6 years, 11 months ago

what is the easiest formula for this kind of equation?

Ayan Naungayan - 6 years, 11 months ago

How we send ques? to others guys

Rahul Yadav - 6 years, 11 months ago

Log in to reply

You can post questions by selecting "Post" in the menu at the top (if you are on your desktop).

Calvin Lin Staff - 6 years, 11 months ago

If you can solve it, or at least you can understand the solution, you can call yourself a privileged person.

Irina Comanescu - 6 years, 11 months ago

So if we were to find, say, the sixth root, we'd multiply the exponent by 1/6?

Ben M - 6 years, 10 months ago

But it also could be 5√5^5^5

Pablo Del Corral - 6 years, 12 months ago

5^5^5 = 5^25, 5^{25/5}, 5^5, 3125

Branislav Dinic - 6 years, 11 months ago

Its 5^5. Lets say the result of 5^5 is 'x'. (Its 3125 actually, but for simplicity). So its now x^5. fifth root of this is x^(5*1/5), which is nothing but 'x'. And as previously stated, x=5^5. So the solution is 5^5

Ashish Vellora Madathil - 6 years, 11 months ago

Log in to reply

nah, exponentiation is right-associative.. it's 5^x, not x^5, so the fifth root is 5^(x/5) = 5^(3125/5) = 5^625 = 5^(5^4)

Engelbert Eric - 6 years, 11 months ago

The expression can be written as:

= 5 5 5 × 1 5 5^{5^{5} \times \frac{1}{5}}

= 5 5 5 × 5 1 5^{5^{5} \times 5^{-1}}

= 5 5 5 1 5^{5^{5-1}}

= 5 5 4 \boxed{5^{5^{4}}}

very easy method thanks

Saaduddin Saad - 6 years, 11 months ago
John Mead
Jun 16, 2014

Given the form of the multiple-choice answers we have, we are asked to find p p such that ( 5 p ) 5 = 5 5 5 (5^p)^5=5^{5^5} . (I)

Observe that ( 5 p ) 5 = 5 p × 5 p × 5 p × 5 p × 5 p (5^p)^5=5^p\times5^p\times5^p\times5^p\times5^p

We may add sum the exponents to find the product of powers:

( 5 p ) 5 = 5 ( p + p + p + p + p ) (5^p)^5=5^{(p+p+p+p+p)} = 5 5 p =5^{5p}

We now return to (I), with a substitution on the left.

5 5 p = 5 5 5 5^{5p}=5^{5^5}

Equating the exponents,

5 p = 5 5 5p=5^5

p = 5 5 5 p=\frac{5^5}{5}

= 5 5 5 1 =\frac{5^5}{5^1}

= 5 5 1 = 5 4 =5^{5-1}=5^4 , so we have as our answer 5 5 4 \boxed{5^{5^4}} .

I just think there are no connection between your solution and root of 5

Hafizh Ahsan Permana - 6 years, 12 months ago

Log in to reply

We wish to find the fifth root of 5 5 5 5^{5^5} , that is to say, the number k k that gives k 5 = 5 5 5 k^5=5^{5^5} . For convenience, I rewrite k = 5 p k=5^p , because the answer choices provided all took that form. I'll admit it is a bit of a cheat. I suppose I should have made the end substitution more clear.

John Mead - 6 years, 11 months ago

Log in to reply

good answer...easay to understand

Salman Munir - 6 years, 11 months ago

Prithwish Bose is saying the rt thing

Keshav Kr - 6 years, 11 months ago
Robert Haywood
Dec 4, 2014
  • 5 5 5 = 5 3125 5 ^ {5 ^ 5}=5 ^ {3125}
  • a k n = a k n \sqrt[n]{a ^ k}=a ^ {\frac{k}{n}}
  • 5 3125 5 = 5 3125 5 = 5 625 = 5 5 4 \sqrt[5]{5 ^ {3125}}=5 ^ {\frac{3125}{5}}=5 ^ {625}=5 ^ {5 ^ 4}
Victor Blancard
May 24, 2016

5 5 5 5 = ( 5 5 5 ) 1 5 = 5 5 5 × 1 5 = 5 5 5 × 5 1 = 5 5 5 1 = 5 5 4 \space\space\space\space \sqrt[5]{5^{5^{5}}} \\ = {(5^{5^5})}^{\frac{1}{5}} \\ = 5^{5^5 \times \frac{1}{5}} \\ = 5^{5^5 \times 5^{-1}} \\ = 5^{5^{5 - 1}} \\ = 5^{5^4}

Mahtab Hossain
Jun 6, 2015

just make it 5^3125 and then find out the fifth root !

Kamran Bhagat
Dec 31, 2014

let 5^(5^5) = a, and b = 5^5, => a^(1/5) = 5^(b * 1/5) = 5^(5^(5-1)) = 5^(5^4).

Julia Winters
Jun 17, 2014

Finding a fifth root is just like dividing the exponent by 5. 5^5=5^4.

i think finding the fifth root is dividing the number five times with five.

Rustom Jr. Soliven - 6 years, 11 months ago

(5^(5^5))^(1/5)=(5^3125)^(1/5)=5^625=5^(5^4)

what does it mean to find out fifth root ?......

Salman Munir - 6 years, 11 months ago

Log in to reply

for those who didnt understand the logic .. tis should help ... they've asked to find the 5th rood of the number 5^5^5 . (5th root means dividng the power by the root value .. here dividing the terms in power by 5) i.e; 5^{(5^5)/5} = 5^625= 5^5^4 Incase u've confusion with the power part then just take the power part and think it like fraction .. i.e; 5^{(5^5)/5} taking only powers for explanation: (5^5)/5 can be written as (5^5)(5^-1)=(5^4) so ans is 5^(5^4) Hope this was helpful :)

Minamino Suechi - 6 years, 5 months ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...