# Math help PLEASE!

Show 40 post(s) from this thread on one page
Page 1 of 2 1 2 Last
• 09-16-2007, 02:10 PM
-Dan-
Can anyone help me with these questions?

1. Write as a product of their prime factors:
a) 420
b) 13457
c) 9240

2. If 1080 = 2x times 3y times 5z, what are the values of x, y and z?

3. What is the only number that has no reciprocal?

4. Express 144 as the product of its factors. Write your answer in index form.

I haven't a clue and it's in for tomorrow. I'll give all of my points to whoever can supply the correct answers. Please; help if you can.
• 09-16-2007, 02:13 PM
RoBz
I believe the answer to number 3 is zero.
• 09-16-2007, 02:14 PM
Siouxsie
The answer to 3. is Zero.
• 09-16-2007, 02:14 PM
NYYFAN
Math is my worse subject by far and I am glad on I dont need one to graduate.

Anyway, I am not sure of them(got an idea) but I am certain 0 is the answer to #3
• 09-16-2007, 02:16 PM
|-Anubis-|
• 09-16-2007, 02:19 PM
RoBz
Number 4.

1 X 12^2

As in one times 12 squared.
EDIT: Wait I'm wrong give me a minute or two I can't remember this stuff.
• 09-16-2007, 02:21 PM
-Dan-
Thanks so much for the help, but does anyone know any of these two:

1. Write as a product of their prime factors:
a) 420
b) 13457
c) 9240

2. If 1080 = 2x times 3y times 5z, what are the values of x, y and z?
• 09-16-2007, 02:23 PM
RoBz
Ok for question 4 I think it's

1.44 X 10 ^2

(one point forty four times ten squared)
• 09-16-2007, 02:25 PM
-Dan-
Which one is 1.44 x10 squared? Number 4?
-= Double Post =-
OK, I saw your edited post, but I'm still stuck on number 1 and 2.
• 09-16-2007, 02:32 PM
Judas
I'd totally help with number two, but I don't have my calculator. When I get back later tonight, I'll set up the TI-84 emulator and figure it out.
• 09-16-2007, 02:32 PM
RoBz
1a.
2 X 3 X 7 X 2 X 5

1b.
I can't get it to work out.

1c.
2 X 2 X 2 X 3 X 5 X 7 X 11

I'm not sure if those are the final answers cause those sums aren't on my course so I haven't done 'em in a few years.
Do you remember anything from school if you group those answers I gave or anything?
• 09-16-2007, 02:34 PM
PopeOfDope
Prime factorisation is easy.
Take 420 for example.

420/2 = 210
210/2 = 105
105/5 = 21
21/7 = 3
3/3 = 1

So your final answer is 2 x 2 x 5 x 7 x 3= 420

Keep divinding your initial number by prime numbers until you get to 1.
• 09-16-2007, 02:36 PM
-Dan-
Thanks, but I gotta go in 20 minutes and I really need the answers. If anyone can help, please do. I'd be so grateful.
• 09-16-2007, 02:41 PM
RoBz
Look I gave 'em to you just I didn't find any prime numbers that divided into 1b.

I should really be doing my own homework lol.
• 09-16-2007, 02:46 PM
-Dan-
Thanks to Pope, I did them (Thanks Pope :)) I just need to do this one in 10 MINUTES:

If 1080 = 2x time 3y times 5z what are the values of x, y and z??

By the way, robzzzz, just in case you wanted to know, 1b was 5 x 5 x 7 x 7 x 11
• 09-16-2007, 02:49 PM
PopeOfDope
Quote:

Originally Posted by -Dan-
Thanks to Pope, I did them (Thanks Pope :)) I just need to do:

If 1080 = 2x time 3y times 5z what are the values of x, y and z??

Do the same thing to 1080, i.e. split it up into its prime factors. Then count how many times 2, 3 and 5 show up. Those are your values for x y and z
• 09-16-2007, 02:53 PM
RoBz
Quote:

Originally Posted by -Dan-
By the way, robzzzz, just in case you wanted to know, 1b was 5 x 5 x 7 x 7 x 11

That gives you 13,475 and in your first post you wrote 13,457.
• 09-16-2007, 02:55 PM
-Dan-
Agh, I'm still stuck

EDIT: I know, I misspelled it.
• 09-16-2007, 02:57 PM
RoBz
How?
Quote:

Originally Posted by PopeOfDope
Do the same thing to 1080, i.e. split it up into its prime factors. Then count how many times 2, 3 and 5 show up. Those are your values for x y and z

Do that.
• 09-16-2007, 02:59 PM
-Dan-
I still don't get it and I've gotta go real soon. Could someone figure out the answer for me pleeease?
• 09-16-2007, 03:00 PM
foXtrot
I wish I was still doing stupid baby math like this. Now its all about proofs and bull nobody gives a crap about.
• 09-16-2007, 03:02 PM
RoBz
Yeah maths get's damn hard.
• 09-16-2007, 03:02 PM
-Dan-
I only need the answer to that ONE question and I'm done.
• 09-16-2007, 03:08 PM
foXtrot
1080 = 2 x 540 = 2 x 2 x 270 = 2 x 2 x 2 x 135 = 2 x 2 x 2 x 5 x 27 = 2 x 2 x 2 x 5 x 3 x 9 = 2 x 2 x 2 x 3 x 3 x 3 x 5

so x = 3, y = 3, and z = 1
• 09-16-2007, 03:33 PM
RoBz
You're welcome.
• 09-16-2007, 03:35 PM
foXtrot
Where are my points and eternal gratitude for my hard work! :down:
• 09-16-2007, 03:37 PM
Dude, how do you have trouble doing these things? I did this in 7th grade.

They're pitifully easy.
• 09-16-2007, 03:41 PM
Anti-QuickJay
Somethings are easier for some people while they are extremely difficult for others.
• 09-16-2007, 03:44 PM
foXtrot
Prime factorization is not a difficult concept to understand... every number is made up of a unique product of primes. Just keep on breaking factors until you get their primes.
• 09-16-2007, 03:46 PM
Anti-QuickJay
But still your going to find people who are troubled in this area.
Show 40 post(s) from this thread on one page
Page 1 of 2 1 2 Last