1. ## Surds

Having trouble solving the following re rationalize denominator & simplify. have answer manual, but cannot figure out how to arrive at the answer.

cube root of x/2 - cube root of x/16. answer is cube root of 4x over 4.

converted equation to: cube root of x divided by cube root of 2 - cube root of x divided by cube root of 16, but from here I am lost.

2. ## Re: Introduction

Originally Posted by retro
Having trouble solving the following re rationalize denominator & simplify. have answer manual, but cannot figure out how to arrive at the answer.

cube root of x/2 - cube root of x/16. answer is cube root of 4x over 4.

converted equation to: cube root of x divided by cube root of 2 - cube root of x divided by cube root of 16, but from here I am lost.
You should post your math questions in the appropriate forum here.

$\displaystyle \sqrt[3]{\frac{x}{2}}-\sqrt[3]{\frac{x}{16}}=\sqrt[3]{x}\left(\frac{1}{\sqrt[3]{2}}-\frac{1}{2\sqrt[3]{2}}\right)= \frac{\sqrt[3]{x}}{2\sqrt[3]{2}}\cdot\frac{\sqrt[3]{4}}{\sqrt[3]{4}}=\frac{\sqrt[3]{4x}}{4}$

-Dan

4. ## Re: Surds

I don't understand how u arrived at the denominator in the equation cubed root of X/2*cube root of 2

Also, please tell me how to insert math symbols

5. ## Re: Surds

Originally Posted by retro
I don't understand how u arrived at the denominator in the equation cubed root of X/2*cube root of 2
Also, please tell me how to insert math symbols
To post symbols learn to use LaTeX

You need to learn the basic algebra of exponents:
$\large{\sqrt[3]{16}=\sqrt[3]{8\cdot 2}=\sqrt[3]{2^3}\cdot\sqrt[3]{ 2}=2\sqrt[3]{2}}$

6. ## Re: Surds

OMG I have so much to learn. Thanks so much