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Peegee
11-10-2010, 04:00 PM
(quiet, asians)

http://i54.:bou::bou::bou::bou::bou::bou::bou::bou::bou::bou::bou::bou:/2euic2f.jpg

x-7 = 19+x
x^2 -7x = 19x + x^2
subtract 19x+x^2 from both sides
-7x - 19x = 0
x = 0 QED

qwertysaur
11-10-2010, 04:46 PM
Incorrect. If you substitute x = 0 then you will get -7 = 19 which is wrong. The correct answer is no solution.
Proof
<pre>
x-7 = 19 + x
-x -x</pre>
-7 = 19, a contradiction indicating no solution.
You can see the fallacy in your work because ito get x=0 you had to multiply everything by x. However assume x is 0 you are simply multiplying everything by zero and all information is lost.

Peegee
11-10-2010, 04:57 PM
Incorrect. If you substitute x = 0 then you will get -7 = 19 which is wrong. The correct answer is no solution.
Proof
<pre>
x-7 = 19 + x
-x -x</pre>
-7 = 19, a contradiction indicating no solution.
You can see the fallacy in your work because ito get x=0 you had to multiply everything by x. However assume x is 0 you are simply multiplying everything by zero and all information is lost.

but I added and mutiplied everything on both sides. Ergo it is valid. x = 0

Hollycat
11-10-2010, 04:58 PM
correct, x=nrn

NorthernChaosGod
11-10-2010, 05:01 PM
Incorrect. If you substitute x = 0 then you will get -7 = 19 which is wrong. The correct answer is no solution.
Proof
<pre>
x-7 = 19 + x
-x -x</pre>
-7 = 19, a contradiction indicating no solution.
You can see the fallacy in your work because ito get x=0 you had to multiply everything by x. However assume x is 0 you are simply multiplying everything by zero and all information is lost.
This, you can see it without doing any work.

but I added and mutiplied everything on both sides. Ergo it is valid. x = 0
It's only valid if you plug it back in and get a valid result. :p

Peegee
11-10-2010, 05:03 PM
I thought I told you guys NO ASIANS

Raistlin
11-10-2010, 05:09 PM
Apparently "asians" are anyone who knows anything about math.

Speaking of which, we haven't had a "does 0.999... = 1?" thread in a while.

NorthernChaosGod
11-10-2010, 06:03 PM
Speaking of which, we haven't had a "does 0.999... = 1?" thread in a while.

Why would you want to do that again? :|

Hollycat
11-10-2010, 06:17 PM
I thought I told you guys NO ASIANS

racist

Raistlin
11-10-2010, 06:23 PM
Speaking of which, we haven't had a "does 0.999... = 1?" thread in a while.

Why would you want to do that again? :|

Because the people who refuse to accept it are always entertaining. And math is fun.

Peegee
11-10-2010, 06:43 PM
Speaking of which, we haven't had a "does 0.999... = 1?" thread in a while.

Why would you want to do that again? :|

Because the people who refuse to accept it are always entertaining. And math is fun.

Regardless I'm correct. x = 0 and 26 = 0 . But x != 26 that would be a fallacy.

qwertysaur
11-10-2010, 07:20 PM
Incorrect. If you substitute x = 0 then you will get -7 = 19 which is wrong. The correct answer is no solution.
Proof
<pre>
x-7 = 19 + x
-x -x</pre>
-7 = 19, a contradiction indicating no solution.
You can see the fallacy in your work because ito get x=0 you had to multiply everything by x. However assume x is 0 you are simply multiplying everything by zero and all information is lost.

but I added and mutiplied everything on both sides. Ergo it is valid. x = 0
If you want to prove that x = 0, then you can't multiply both sides of the equation by x to get that solution, because it will always result in 0 = 0. (Side note you also can't divide by x to prove x = 0 because dividing by zero results in no solution.) Take for example x+1 = 2. It should be obvious that x = 1, but lets go with pg's method. Multiply everything by x to get x<sup>2</sup>+x = 2x. Subtract 2x from both sides and you get x<sup>2</sup>-x = 0. Factor and you have (x)(x-1) = 0, giving the solutions x=0 and x=1. However, if x=0 then you get 1 = 2 which is a contradiction.

There are many problems where you have to reject a solution because an answer makes no sense. For example you have a rectangle where the length of one side is three units less than that of the other, and the area is found to be 4 square units. You get (x)(x-3) = 4, which becomes x<sup>2</sup>-3x = 4. Subtract 4 form both sides to get x<sup>2</sup>-3x-4 = 0. Factor to get (x-4)(x+1) = 0. So x = 4 or x = -1. You have to reject x = -1 because you can't have a side with negative length.

Remember to always check to make sure your solutions actually make sense. Also when using an esoteric process for finding the solution, make sure there is no way that is easier first. Don't use calculus to find the area of a circle, just use A = πr<sup>2</sup>. The calculus method is possible, but much more time consuming.

Peegee
11-10-2010, 07:32 PM
Incorrect. If you substitute x = 0 then you will get -7 = 19 which is wrong. The correct answer is no solution.
Proof
<pre>
x-7 = 19 + x
-x -x</pre>
-7 = 19, a contradiction indicating no solution.
You can see the fallacy in your work because ito get x=0 you had to multiply everything by x. However assume x is 0 you are simply multiplying everything by zero and all information is lost.

but I added and mutiplied everything on both sides. Ergo it is valid. x = 0
If you want to prove that x = 0, then you can't multiply both sides of the equation by x to get that solution, because it will always result in 0 = 0. (Side note you also can't divide by x to prove x = 0 because dividing by zero results in no solution.) Take for example x+1 = 2. It should be obvious that x = 1, but lets go with pg's method. Multiply everything by x to get x<sup>2</sup>+x = 2x. Subtract 2x from both sides and you get x<sup>2</sup>-x = 0. Factor and you have (x)(x-1) = 0, giving the solutions x=0 and x=1. However, if x=0 then you get 1 = 2 which is a contradiction.

There are many problems where you have to reject a solution because an answer makes no sense. For example you have a rectangle where the length of one side is three units less than that of the other, and the area is found to be 4 square units. You get (x)(x-3) = 4, which becomes x<sup>2</sup>-3x = 4. Subtract 4 form both sides to get x<sup>2</sup>-3x-4 = 0. Factor to get (x-4)(x+1) = 0. So x = 4 or x = -1. You have to reject x = -1 because you can't have a side with negative length.

Remember to always check to make sure your solutions actually make sense. Also when using an esoteric process for finding the solution, make sure there is no way that is easier first. Don't use calculus to find the area of a circle, just use A = πr<sup>2</sup>. The calculus method is possible, but much more time consuming.

oh EoFF :love:

ps aren't you aznnnn?

escobert
11-10-2010, 07:33 PM
math is for losers.

Peegee
11-10-2010, 07:40 PM
math is for losers.

and bert. asl?

qwertysaur
11-10-2010, 08:22 PM
I'm not AZN pg :p

Peegee
11-10-2010, 08:54 PM
I'm not AZN pg :p

Yet you did math. QED

Shlup
11-10-2010, 09:02 PM
Aww, I was hoping you were posting a real equation for me to solve. I miss algebra. ;_;

Mirage
11-10-2010, 09:12 PM
I consider 0 = 26 a completely valid answer. Just as valid as for example "tuesday".

Peegee
11-10-2010, 09:13 PM
Aww, I was hoping you were posting a real equation for me to solve. I miss algebra. ;_;

It is a real equation.
Fine here's another:

x-7 = x+9 . Solve for x.

Raistlin
11-10-2010, 09:16 PM
X is obviously a quantum number without a fixed value.

Peegee
11-10-2010, 09:55 PM
X is obviously a quantum number without a fixed value.

now now we don't need to be mean. Stephen Hawking already established that everything in the past exists in simultaneously plausible possibility until it is measured.

So x is whatever we determine it to be now, and the past will adapt to our fiction. Christianity 1, atheists 0

Hollycat
11-10-2010, 10:01 PM
x is whatever you want it to be, I think its chocolate mint ice cream with butterfinger sprinkled on top, next to seasons 1-8 of Monk on dvd

Mirage
11-10-2010, 10:24 PM
I already established that x = tuesday. Stop spreading misinformation.

oh btw
which anime is that from?

rubah
11-11-2010, 01:55 AM
that's cool, qwerty. I was trolling PGies when I gave him the x=0 proof, but your posts are pretty interesting!

NorthernChaosGod
11-11-2010, 02:05 AM
I hate you for spitting in the face of basic algebra, PG.

Shlup
11-11-2010, 02:10 AM
I consider 0 = 26 a completely valid answer. Just as valid as for example "tuesday".

http://i194.photobucket.com/albums/z108/btbrian14/Gifs/Reaction/ColbertNoWay-1.gif

Peegee
11-11-2010, 03:45 AM
that's cool, qwerty. I was trolling PGies when I gave him the x=0 proof, but your posts are pretty interesting!

Rodarian
11-11-2010, 06:33 AM
I use to love maths..Right up till grade ten...I got a horrible math teacher that belittle me if I got it wrong....

After that I stopped liking math...

Now I'm just a dumb purazn... :(

Mirage
11-11-2010, 11:50 AM
I consider 0 = 26 a completely valid answer. Just as valid as for example "tuesday".

Image

What do you mean? Please elaborate. I bet that guy isn't even a real teacher, so how would he know?!

Shlup
11-11-2010, 03:59 PM
Stephen Colbert knows everything. Especially America things. Like maths.

Alive-Cat
11-11-2010, 05:36 PM
Okay, okay, guys, I come clean. I am x. :)

NorthernChaosGod
11-11-2010, 06:34 PM
Okay, okay, guys, I come clean. I am x. :)

I found x!

Alive-Cat
11-11-2010, 06:58 PM
NorthernChaosGod wins the thread!

Peegee
11-11-2010, 08:00 PM
NorthernChaosGod wins the thread!

What are you 12? asl op

NorthernChaosGod
11-12-2010, 01:26 AM
NorthernChaosGod wins the thread!

What are you 12? asl op

Have a seat over there.

Peegee
11-12-2010, 07:55 PM
NorthernChaosGod wins the thread!

What are you 12? asl op

Have a seat over there.

No. You're not my mommy