# Thread: Need abit of help with simplifying

1. ## Need abit of help with simplifying

Hi everyone,

I am trying to brush up with my maths and i have not done that bad at working some questions out, but i am stuck on a certain question and i can not work it out to be the answer that the website saying the question gives you.

The question is simplify

$sqrt(90) x sqrt(600000)$

$3000 sqrt(6)$

I have got to

$sqrt(90) x sqrt(600000) = sqrt(54000000)$

But i can not work out how to simplify that

Any help will be great

Thanks

2. ## Re: Need abit of help with simplifying

Originally Posted by sentel
Hi everyone,

I am trying to brush up with my maths and i have not done that bad at working some questions out, but i am stuck on a certain question and i can not work it out to be the answer that the website saying the question gives you.

The question is simplify

$sqrt(90) x sqrt(600000)$

$3000 sqrt(6)$

I have got to

$sqrt(90) x sqrt(600000) = sqrt(54000000)$

But i can not work out how to simplify that

Any help will be great

Thanks
$\sqrt{90} \cdot \sqrt{600000}$

$\sqrt{9 \cdot 10} \cdot \sqrt{10000 \cdot 4 \cdot 15}$

$\sqrt{9} \cdot \sqrt{10} \cdot \sqrt{10000} \cdot \sqrt{4} \cdot \sqrt{15}}$

$3 \cdot \sqrt{10} \cdot 100 \cdot 2 \cdot \sqrt{15}}$

$600 \sqrt{10 \cdot 15}$

$600 \sqrt{25 \cdot 6}$

$600 \sqrt{25} \cdot \sqrt{6}$

$600 \cdot 5 \cdot \sqrt{6}$

$3000 \sqrt{6}$

3. ## Re: Need abit of help with simplifying

Originally Posted by sentel
Hi everyone,

I am trying to brush up with my maths and i have not done that bad at working some questions out, but i am stuck on a certain question and i can not work it out to be the answer that the website saying the question gives you.

The question is simplify

$sqrt(90) x sqrt(600000)$

$3000 sqrt(6)$

I have got to

$sqrt(90) x sqrt(600000) = sqrt(54000000)$

But i can not work out how to simplify that

Any help will be great

Thanks
Alternatively you can factor 54000000 into terms that are easier to deal with

$\sqrt{54 \times 10^6} = \sqrt{54} \times \sqrt{10^6} = \sqrt{9} \times \sqrt{6} \times \sqrt{10^6}$
$= 3 \times 1000 \times \sqrt{6} = 3000\sqrt{6}$

4. ## Re: Need abit of help with simplifying

Thank you thats brilliant

5. ## Re: Need abit of help with simplifying

Just a quick question how did you get

$600\sqrt{25 \cdot 6}$

from

$600\sqrt{10 \cdot 15}$

Thanks

6. ## Re: Need abit of help with simplifying

Originally Posted by sentel
Just a quick question how did you get

$600\sqrt{25 \cdot 6}$

from

$600\sqrt{10 \cdot 15}$

Thanks
$25 \times 6 = 10 \times 15 = 150$. In other words 25 and 6 are factors of 150 like 10 and 15.

Alternatively you can split 10 and 15 into their factors $10 \times 15 = (2 \times 5) \times (3 \times 5) = 6 \times 25$

7. ## Re: Need abit of help with simplifying

Arh doh thank you