Algebra help please!!

C

cphillips

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When I was in highschool I used to enjoy math and found algebra to be easy and fun to do, that was over 10 years ago, now going back to complete my highschool education I feel like I'm starting all over again. :?

Please help to refresh my memory.

The question is

Factor each of the following completely.

1) a^3 -4a

With this question the only thing i can think of doing is subtracting the exponent making the answer -4a^2
am I doing this right? Or do I have to do more to factor it completely.
 
cphillips said:
When I was in highschool I used to enjoy math and found algebra to be easy and fun to do, that was over 10 years ago, now going back to complete my highschool education I feel like I'm starting all over again. :?

Please help to refresh my memory.

The question is

Factor each of the following completely.

1) a^3 -4a

With this question the only thing i can think of doing is subtracting the exponent making the answer -4a^2
am I doing this right? ...No

Or do I have to do more to factor it completely.
Click to expand...

Please go to:

http://www.purplemath.com/modules/simpfact.htm

for a quick review.
 
thanks for the link, I forgot about factoring.

would this be correct then: -4a + a^3 ?

and to factor this next question

x^2 -x -6

would be: -6 + -x +2x
 
please forgive the stupidity, like I said before its been a real long time since I've done any of this, and looking at some of the geometry and trig I'll have coming up just makes my head hurt alittle being that it's going to be even more complex then what I'm doing now. :?

Thanks again for the help and links :D
 
cphillips said:
thanks for the link, I forgot about factoring.

would this be correct then: -4a + a^3 ?
Click to expand...
All you've done is rearrange the terms. You haven't factored anything yet. :shock:

There is a common factor. Review the link provided earlier for this topic, and then try to factor out the common term. (Put the terms back in their original order before you do this, though.)

Then study the "special factoring" link (provided earlier) in order to factor the resulting difference of squares.
 
Yeah i did just re-arange the equation but that was the answer an online calculator gave me that i used, when trying figure things out forgeting about the difference with quadric equations. I finally did figure out the answer, being: (x-2)(x+3).

And thanks for the video links.
 
cphillips said:
… I feel like I'm starting all over again …
Click to expand...


With respect to the high-school level math topics, you are starting over, so it's completely normal to feel that way.

Are you already enrolled in some type of GED program at a Community College?

Are you self-studying, in preparation for enrolling in such a program?

 
cphillips said:
And thanks for the video links.
Click to expand...
AHHHHHHHHH....I knewwwwwwwww it would help :idea:

How did ya handle this baby: a^3 - 4a?

a(a^2 - 4) is 1st step; ok?

What's next?
 
I'm wanting to achive my highschool graduation through at home correspondence, I'm a mother of 3 young children so doing my schooling at home is the best way for me to complete it and be there for my children. Right now I'm working on a practise exercise worksheet to see what I know and what I need to refresh my memory on and also for what course they should put me in.


Sorry I didn't respond earlier, been watching LOTS of videos :D but the answer I came up with for factoring: a^3-4a = a(a-2)(a+2)
 
cphillips said:
Sorry I didn't respond earlier, been watching LOTS of videos :D but the answer I came up with for factoring: a^3-4a = a(a-2)(a+2)
Click to expand...
Good one, Mom...there's still hope for you :wink:
 
Mom, these "factor" things kinda go this way:

some teacher wrote down something like (2x + 3)(x - 5)

then multiplied it out: 2x^2 + 3x - 10x - 15 ; 2x^2 - 7x - 15

then told YOU: factor this : 2x^2 - 7x - 15

and YOU have to come up with what he multiplied out....
 
Ok, so I'm starting to get used to factoring like terms with the same variable again but this next one I'm realy stumped on, has no GCF and the variables are different, been looking at so many vid's and other algebra help sites trying to find an equation similar and so far haven't, please help!!

Need to factor each completey:

1) 6x^2 +13x -5= (3x -1)(2x+5) I think i got this 1 ??
x=1/3 x=-5/2

2) 9x^2 - 16y^2= This one the only thing in common is the ^2 but trying to work it out this doesn't work, (x-y)(9x - 16y), and I have no clue what else to do for this


3) 16x^2 - 24xy + 9y^ This one I had no clue where to even begin
 
cphillips said:
1) 6x^2 +13x -5= (3x -1)(2x+5) I think i got this 1 ??
x=1/3 x=-5/2

Correct. You can make sure you're correct by multiplying out your 2 factors:
3x - 1
2x + 5
======
-5 + 15x (multiply top by 5)
-2x + 6x^2 (multiply top by 2x)
Add 'em up: -5 + 15x - 2x + 6x^2 = 6x^2 + 13x - 5 : voila!

2) 9x^2 - 16y^2= This one the only thing in common is the ^2 but trying to work it out this doesn't work,
(x-y)(9x - 16y), and I have no clue what else to do for this.

Real easy: go here:
http://www.google.ca/search?hl=en&sourc ... ference+of
Are you ok now?

3) 16x^2 - 24xy + 9y^2 This one I had no clue where to even begin

Try 16x^2 - 24x + 9 ; get my drift?
Click to expand...
 
cphillips said:
3) 16x^2 - 24xy + 9y^2 This one I had no clue where to even begin
Click to expand...
You would factor this in exactly the same way that you would factor 16x[sup:ablvqhu9]2[/sup:ablvqhu9] - 24x + 9, except that your factors will have a "y" at the ends, instead of only an "x" at their beginnings. :wink:

Hint: Perfect square trinomial....
 
Is this right or can i factor this even more to be completely factored.

9x^2 -16y^2= ( 3x -4y)(3x +4y)

16x^2 -24xy +9y^2= (3y -4x)(3y-4x)
 
Once you get down to linear expressions (such as 3x + 4), and as long as nothing factors out (as would happen with 2x + 4), you're done! :wink:
 
Great, thx so much everyone mabe I won't be quite so lost once I actually start a course where algebra is concerned now on to remembering geometry and trig :?
 
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