SOLUTION: okay so how do i simplify the square root of 128? i know it has something to do with prime numbers i was thinking product rule using 4, 2 and sixteen but i am not sure what to do a

Algebra.Com
Question 171503: okay so how do i simplify the square root of 128? i know it has something to do with prime numbers i was thinking product rule using 4, 2 and sixteen but i am not sure what to do after that or how to write it!
Found 4 solutions by stanbon, jim_thompson5910, Mathtut, Alan3354:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
how do i simplify the square root of 128
The prime number breakdown of 128 is
128 = 2*64
= 2*2*32*
= 2*2*2*16
= 2*2*2*2*8
---
---
= 2*^7
------------
So sqrt(128) = sqrt(2^7)
= sqrt(2*6)*sqrt(2)
= 2*^3*sqrt(2)
= 8sqrt(2)
-----------------
A shorter way to go is
sqrt(64*2) = sqrt(64)*sqrt(2)
= 8*sqrt(2)
================
Cheers,
Stan H.

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!

Start with the given expression



The goal of simplifying expressions with square roots is to factor the radicand into a product of two numbers.


One of these two numbers must be a perfect square. When you take the square root of this perfect square, you will get a rational number.


So let's list the factors of 128


Factors:
1, 2, 4, 8, 16, 32, 64, 128


Notice how 64 is the largest perfect square, so lets factor 128 into 64*2


Factor 128 into 64*2



Break up the square roots using the identity



Take the square root of the perfect square 64 to get 8



So the expression simplifies to

----------------------------
Check:


Notice if we evaluate the square root of 128 with a calculator we get





and if we evaluate we get





This shows that . So this verifies our answer

Answer by Mathtut(3670)   (Show Source): You can put this solution on YOUR website!
==
Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
okay so how do i simplify the square root of 128? i know it has something to do with prime numbers i was thinking product rule using 4, 2 and sixteen but i am not sure what to do after that or how to write it!
-------------------

=
=
=
The object of the game is to make the number under the radical as small as possible.

RELATED QUESTIONS

okay so how do i simplify the square root of 128? i know it has something to do with... (answered by solver91311)
okay i dont know how to do the whole typy in htingy but it says "the square root of x+2 (answered by stanbon)
Okay, So i have a Quiz tommorrow and i dont know exactly What to do when it comes to... (answered by ankor@dixie-net.com)
How do I square root (without using a calculator) a number when every time I factor it, I (answered by ccs2011)
how do i do the square root of 5 over 7? I need to simplify... (answered by robertb)
Please can you help me with Operations with Radical Expressions because I don't know how... (answered by jim_thompson5910)
This word problem pertains to "REVENUE". The demand for a certain product is given by... (answered by jaydducote)
How do I explain the answer to this question? I am thinking of two numbers. When they... (answered by vleith)