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.

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

-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:
$\large{\sqrt{16}=\sqrt{8\cdot 2}=\sqrt{2^3}\cdot\sqrt{ 2}=2\sqrt{2}}$

6. Re: Surds

OMG I have so much to learn. Thanks so much