Annoyed at thread drift

Status
Not open for further replies.
Agree, but math isn't high tech. Most people understand when you want to find the answer to a problem, certain basic steps should be followed. Let me give you an example:

[(3x^2-27)divided by 4)] times[ 8x^2) divided by(9-3x)]divided by [(x^2+3x) divided by 6]

Ok, to find the answer we can invert the third fraction then multiply straight across like this

(3x^2-27)(8x^2) 6
-------------------------------------
4(9-3x) (x^2+3x)


but first we can factor and cross cancel

(3(x-3)(x+3)(8x^2) 6
--------------------------------------...
-12(x-3) x (x+3)

after we cross cancel we get

=-12x


Or, to make it simpler, we can start by inverting the last fraction and multiplying:

3x² - 27 .. 8x² ....... 6
----------- * -------- * ----------
.... 4 ...... 9 - 3x . x² + 3x

Now you can do some factoring and canceling:
3(x² - 9) .. 8x² ...... 6
----------- * -------- * ----------
.... 4 ..... 3(3 - x) . x(x + 3)

You can cancel the 4 with the 8, remove the 3's and the x's.
(x² - 9) .... 2x ........ 6
----------- * -------- * ----------
.... 1 ...... (3 - x) . (x + 3)
Now x²-9 is a difference of squares which can be rewritten as (x - 3)(x + 3):

(x-3)(x+3) .... 2x ........ 6
-------------- * -------- * ----------
....... 1 ...... (3 - x) . (x + 3)

Cancel the x+3:
(x - 3) .. 2x .... 6
------- * -------- * ---
...1 ... (3 - x) .. 1

Now notice if you factor out a -1, you have 3-x which will cancel:
-1 .. 2x .. 6
--- * ---- * ---
.1 ... 1 ... 1

Multiply across and you get:
-12x

So you see, there isn't really anything high tech about it. It's just math and it's just plain fun. :rolleyes:

You are an evil, twisted person. When I was in school, right after the War of 1812, people like you were sometimes found in their lockers months later. :D:D
 
Where's the original poster when we need him to keep this drifting??

My misses is a great cook.
 
The Drifters, now that was a great movie.... Or was that the Grifters? No matter...
 
My tuxedo cat got out and came back the other day. Some weird person shaved her belly and private parts. Sometimes you just gotta wonder who all is out there. Frank
 
My tuxedo cat got out and came back the other day. Some weird person shaved her belly and private parts. Sometimes you just gotta wonder who all is out there. Frank
That is too strange! Lucky the cat came home I think. Sick ones are out there for sure.:eek:
 
Status
Not open for further replies.

Latest posts

Back
Top