Sqrt 128x^9y^16/[16x^2y]? #Simplify

2 Answers
Sep 3, 2017

frac(sqrt(2 x^(5)) y^(7))(8)2x5y78

Explanation:

We have: frac(sqrt(128 x^(9) y^(16)))(16 x^(2) y)128x9y1616x2y

= frac(sqrt(128) cdot sqrt(x^(9)) cdot sqrt(y^(16)))(16 x^(2) y)=128x9y1616x2y

= frac(8 sqrt(2) cdot sqrt(x^(9)) cdot y^(8))(16 x^(2) y)=82x9y816x2y

= frac(8 sqrt(2) y^(8) cdot sqrt(x^(9)))(16 x^(2) y)=82y8x916x2y

= frac(sqrt(2) y^(7))(8) cdot (x^(frac(9)(2) - 2))=2y78(x922)

= frac(sqrt(2) y^(7))(8) cdot (x^(frac(5)(2)))=2y78(x52)

= frac(sqrt(2) y^(7))(8) cdot sqrt(x^(5))=2y78x5

= frac(sqrt(2 x^(5)) y^(7))(8)=2x5y78

Sep 3, 2017

I different interpretation of the question to that by Tazwar Sikder

2x^3y^7sqrt(2xy) color(white)(ddd)2x3y72xyddd Answer checked and confirmed

Explanation:

Assumption: the question is meant to read:

sqrt((128x^9y^16)/(16x^2y)128x9y1616x2y

If you are ever not sure about the roots of a large number do a rough sketch of a prime factor tree.
Tony B

Write as:

(sqrt(128x^9y^16))/(sqrt(16x^2y))128x9y1616x2y

This is the same as

(sqrt((2^2)^3xx2xx (x^2)^4xx x xx(y^2)^8))/(sqrt(4^2xx x^2xxy)(22)3×2×(x2)4×x×(y2)842×x2×y
color(white)("d")d

(2^3x^4y^8sqrt(2x))/( 4xsqrt(y)) 23x4y82x4xy

Cancel out the 4x4x in the denominator

(2x^3y^8sqrt(2x))/( sqrt(y)) 2x3y82xy

Multiply by 1 but in the form of 1=sqrt(y)/sqrt(y)1=yy

(2x^3y^8sqrt(2xy))/y 2x3y82xyy

Cancel out the yy in the denominator

2x^3y^7sqrt(2xy) 2x3y72xy
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Check by substituting arbitrary values for x and yxandy

I choose x=2; y=2x=2;y=2

sqrt((128x^9y^16)/(16x^2y)=5792.61875.....

2x^3y^7sqrt(2xy) =5792.61875.... color(red)(larr" It works")