easy factoring problem, i'm just stupid!

[AlphaIVT]

how do I factor out:

a. x^8-y^8


b. 36 - (x-5)^2


c. 81 - (2x+7)^2


Please show the steps for each, so I can do the rest without bugging you anymore

 

[lesterjr]

a. x*x*x*x*x*x*x*x - y*y*y*y*y*y*y*y

b. 2*2*3*3 - (x-5)(x-5)

c. 3*3*3*3 - (2x+7)(2x+7)

 

[AlphaIVT]

hm... not like that

heres an example:

x^2+4x+4 = (x+2)(x+2)

 

[thereds]

x^8 - y^8
[(x^4)^2] - [(y^4}^2]
say, a = x^4 and b = y^4
a^2 - b^2
therefore, (a+b)(a-b)
unsubstitute, and you have an answer for part a.

now, I have to go to the bathroom. nature calls.

be back later.

 

[axelfox]

Hahah, they don't teach you jack at Marina, eh?

I just remember, my cousin goes over there for Spanish 5 a couple of days a week.

BTW, do you know a Jackie Tran?

 

[AlphaIVT]

yeah, I know her, she's in my English class. Whoa! This is getting freaky!

lol, thereds, thanks for the help man, you happen to know how to do the others too right?

 

[SSP]

I'll just tell you how to do it. I ain't gona do your homework for ya.

Eg:

(x-2)^2

1) Take the first number (which in this case is x. It might be 2x, depends on the question) and square it. so you get x^2.

2) Take the 2nd number, multiply it by the first number (in this case, its 2 because 2 x 1 is 2 (remember the invicible 1 in front of the 'x'), and multiply the answer by 2 (always 2, it does not change). So the answer is 4.

3) take the second number and square it. The answer... 4.

Now put them together... X^2 - 4X + 4

If you can't understand the above instuctions, then you need help.

 

[thereds]

aww c'mon SSP.
hehe.

should I do the rest?

follow the instructions Alpha. It's simple stuff.

 

[BiggieN]

<< i'm just stupid! >>




um...couldn't have said it better myself.



















j/k. now why are you forming a clan to fight those against you here in ATOT? i don't think you can get enough people.

 

[AlphaIVT]

I can't do b..

This is what I've got, its wrong though.

36-(x-5)^2
36-(x^2-10x+25)
36-x^2+10x-25
-x^2+10x-11
(x-1)(x+11)

that is right right? the thing I'm stuck on is what do I do with the negative sign in front of x^2

now for c....

 

[lesterjr]

I asked my almighty TI-92 to factor(36-(x-5)^2)
and it told me...

-(x-11)(x+1)

 

[thereds]

thats right.

 

[AlphaIVT]

answer in book says:

(x+1)(11-x)

how'd they differ? or are they the same?

anyhow, THANKS EVERYONE FOR THE HELP I greatly appreciate it!

 

[Regine]

(a^2-b^2)=(a+b)(a-b)
So:
36 - (x-5)^2
= (6-(x-5))*(6+(x-5))
You can figure out the rest.



You should be glad that some of us &quot;rabid whores&quot; are still nice enough to help you out.

 

[thereds]

dude,
if you don't know your simple - and + calculations, you have more problems to worry about.

 

[thereds]

simple lesson
note: * stands for multiplication if you didn't know.

+ * - = -
+ * + = +
- * - = +
- * + = - (duh)

 

[AlphaIVT]

oh, didn't pay attention to it. damn, i'm so stupid! Took me 10 seconds to stare at my problem, then came to the conclusion hehe.

 

[BiggieN]

hahah...us rabid whores...i'm no whore. i am a paid escort.

 

[Theslowone]

And if you don't understand what he said, yes they are the same.

 

[Mday]

(x^8-y^8) = (x^4+y^4)(x^4-y^4)
(x^4-y^4) = (x^2+y^2)(x^2-y^2)
(x^2-y^2) = (x^1+y^1)(x^1-y^1)

(x^8-y^8) = (x^4+y^4)(x^2+y^2)(x^1+y^1)(x^1-y^1)

--

as for the others, work out the powers and then combine, then factor you dumbass

synthetic division works if you know how to use it... also, some\one of the factors of the constant of the polynomial (both real and imaginary are roots, if there are any) to the polynomial equation...

as for (11-x) and -(x-11), they are the same, -(x-11) = -x-(-11) = -x+11 = 11-x

 

[AlphaIVT]

lol Mday I got it now.

 

[Pretender]

<< synthetic division works if you know how to use it. >>

Wow, you college people still use/remember synthetic division? I thought only us lowly HS students use it.

 

[Mucman]

I use synthetic division all the time in my linear algebra class... I use it for getting eigen values...

 

[Pretender]

b. 36 - (x-5)^2
-(x^2 - 10x +25)+36
-x^2+10x-25+36
-(x^2-10x-11)
-((x-11)(x+1))


c. 81 - (2x+7)^2
-(4x^2+28x+49)+81
-4x^2-28x-49+81
-(4x^2+28x-32)
-((4x-4)(x+8))
-(4(x-1)(x+8))

 

[AlphaIVT]

thanks Pretneder, seemd like I got them right You guys are pure geniouse!