Computer Forums Maths Help pl0x. Quite easy, i think
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 03-08-2008, 04:27 AM #1 ~~~~~~~~   Join Date: Jan 2005 Location: Wales Posts: 5,556 Maths Help pl0x. Quite easy, i think OK, So i have test come monday. I've just moved school's, and they have covered things i hadnt done in my old school. Please dont laugh at me about this, i know it's supposed to be pretty simple... But i'm having trouble with Factoring. I can do some easyer things, but i've got some questions below: 2h^2-15h-27 2k^2-15k+27 6a^2+7a-5 To practice with. I could just use an algebra calculator thingimabob, but that wouldnt teach me anything. Could somone answer these for me, and explain how they did it? Thanks j03 __________________
 03-08-2008, 05:17 AM #2 In Runtime   Join Date: Oct 2007 Posts: 333 Re: Maths Help pl0x. Quite easy, i think (2h+3)(h-9) (2k-9)(k-3) (3a+5)(2a-1) Always find the LCM of the outside number first IE 6a^2+7a-5 'outside number' is 6 LCM is 3 and 2. -5 is the Multiple and +7a is the sum. So from just that I know it will be (3a )(2a ) Which I would write on the paper first, since you find the LCM first. Then I would go (3a+5) because 15a + 3a = 18a not 7a. So the other half has to be (2a-1) because the multiple is negative and a negative*positive is always a negative. breakdown of the other two. 2h^2-15h-27 LCM of 2 is 2 and 1. So (2h )(h ) Multiple is 27. Sum is 15. 9*3 = 27 One has to be positive one has to be negative. +6-9=-3 which isnt 15 So can't be (2h-9)(h+3) So it has to be (2h+3)(h-9) then the other question is the same question but the multiple is +27 not -27. So they both have to be negative. And since -18-3 =-21 not 15 it has to be (2k-9)(k-3) __________________
 03-08-2008, 06:08 AM #3 In Runtime   Join Date: Oct 2007 Posts: 333 Re: Maths Help pl0x. Quite easy, i think Broke it down for you.
 03-08-2008, 06:36 AM #4 ~~~~~~~~   Join Date: Jan 2005 Location: Wales Posts: 5,556 Re: Maths Help pl0x. Quite easy, i think Thank's Man. I will look over that in a bit. I really appreciate it. +1
 03-08-2008, 12:20 PM #5 Guru     Join Date: Jan 2008 Location: U.S. Posts: 7,841 Re: Maths Help pl0x. Quite easy, i think Dude, what the lastwolf said pretty much sums it up. If you're good at doing stuff in your head then it is much quicker to do simple trial and errors mentally to narrow down your opitions rather than writing all that stuff out. Once I learned the principle I just had a calculator do it for me.
03-08-2008, 12:30 PM   #6
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Join Date: Nov 2007
Posts: 395
Re: Maths Help pl0x. Quite easy, i think

Quote:
 Originally Posted by JogaBonito1502 Dude, what the lastwolf said pretty much sums it up. If you're good at doing stuff in your head then it is much quicker to do simple trial and errors mentally to narrow down your opitions rather than writing all that stuff out. Once I learned the principle I just had a calculator do it for me.
Hey how long have you had a reputation beyond repute? I knew you had 2 bars is that automatically reputation beyond repute?

 03-08-2008, 12:33 PM #7 Guru     Join Date: Jan 2008 Location: U.S. Posts: 7,841 Re: Maths Help pl0x. Quite easy, i think Dude I have no idea. One day I was at 98 rep. points, next thing I log on I'm at 136. So, I can't really tell you. Sorry mate.
03-08-2008, 01:16 PM   #8
In Runtime

Join Date: Oct 2007
Posts: 333
Re: Maths Help pl0x. Quite easy, i think

Quote:
 Originally Posted by JogaBonito1502 Dude, what the lastwolf said pretty much sums it up. If you're good at doing stuff in your head then it is much quicker to do simple trial and errors mentally to narrow down your opitions rather than writing all that stuff out. Once I learned the principle I just had a calculator do it for me.
Yeah, I do it all in my head. It was harder to explain than actually doing the questions.
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