Melody

What is 8 ∙ 10-4 divided by 2 ∙ 102?

$$8\times10-4\div 2 \times102\\\\
=80-2\times102\\\\
=80-204\\\\
=-124$$

I got the same answer as you anonymous but it doesn't help learning take place if you only give an answer.

I don't want to just do this person's homework.  I want to give them the chance to learn how it is done. 

$$A=\frac{1}{2}\times bh\\\\
\mbox{multiply both sides by 2}\\
2A = bh\\
\mbox{divide both sides by h}\\
\frac{2A}{h}=b$$

Re: how much percentage (off) of $45.90 is $30.00?

I don't know what the 'off' is there for.  I am assuming it is a typo.

The fraction is   30/45.90

So the percentage is 30/45.9 * 100%

You can finish it.

(-5-7i)-(-8+4i)

=-5-7i+8-4i

=-5+8-7i-4i

=3-11i

This is a very important peice of information.  

My virtual self needs a virtual sugar fix.  Please do not let my spectre go without nutritian. 

These relate to converting decimals to fractions.

Yes, that would make my head hurt too.  

Re:  what is the root for y=(x+3)(x-1) 

The roots are the x intercepts and the equation of the x axis is y=0

So you need to solve y=0 and y=Re: what is the root for y=(x+3)(x-1)   simultaneously.

that is, you must solve 0=(x+3)(x-1)

If 2 things multiply together to give 0 then one or both of them must be 0

so the only possible solutions are 

x+3=0   and   x-1=0

so x=-3  and    x=1   are the roots.

Re: √ How can I get without using calculator

Even a calculator will only give you an approximate answer for most square roots.  For, most square roots are irrational numbers and can not be expressed exactly in number form.

Can you give a specific example of a question?

Tues 15th April 2014.

Hi everyone,

And, the questions just kept coming.  It was just starting to get this busy a few weeks ago but then the forum went deadly quiet. Now suddenly the questions are coming think and fast.  Why is that?  Was there a problem with the old forum that was blocking posting or is it just a strange seasonal phenomenon?  Maybe Andre knows, for I do not.

Anyway, there were lots of great answers from admin, Alan, (Chris and CPhill - another twin?), Bertie, yanes27, reinout-g, SpawnofAngel, deriam2kgmailcom.  I thought Kitty was there too.  Thank you everyone.  You all do a great job.  Over the last few days I am especially thankful to you Chris.  There is no way I could have coped without you.

There are a lot of new members as well but i haven't been able to keep up with you all.  Welcome to the forum.  This forum is in the middle of a very comprehensive overhaul.  It is slowly coming together.  The site's designer Andre Massow is working long hours to try and remove the bugs and polish the final product.  There is still a lot to do but over the past 48 hours it has vastly improved and I am sure it will continue to do so for a while yet.  The private messaging is still not working.  That, I believe is his main task at present.  Thank you Andre.

The main forum tab is sorted on start date for the thread.  Now Andre has introduced a new tab where the most recent posts are sorted on post time.  This is something that the answerers really wanted but I think it needs to display more than just one page.  A page may only reflect a few hours activity.

I now have some moderator privileges.  Thank you Andre. I don't really understand them yet but I can make a post invisable to the rest of the forum and I can give a green tick to indicate when a question has been well answered.  If I tick a question I am not sure if it can still be added to.  Plus when I do this numbers get allocated and I don't understand their significance.  I have ticked a few posts and Andre has also ticked some.  Anyway it will take me a while to work out how to best use these privileges and in the mean time I will continue to use many of my old techniques. Any guidance from you will be appreciated.

I am sure that there are many more things that i need to discuss but I cannot think of what they are at present. 

Good night/day.

Melody.