(quiet, asians)
http://i54.:bou::bou::bou::bou::bou:...u:/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
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(quiet, asians)
http://i54.:bou::bou::bou::bou::bou:...u:/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
Incorrect. If you substitute x = 0 then you will get -7 = 19 which is wrong. The correct answer is no solution.
Proof
x-7 = 19 + x
-x -x
-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 = 0Quote:
Originally Posted by qwertysaur
correct, x=nrn
This, you can see it without doing any work.Quote:
Originally Posted by qwertysaur
It's only valid if you plug it back in and get a valid result. :pQuote:
Originally Posted by Peegee
I thought I told you guys NO ASIANS
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.
Why would you want to do that again? :|Quote:
Originally Posted by Raistlin
racistQuote:
Originally Posted by Peegee
Because the people who refuse to accept it are always entertaining. And math is fun.Quote:
Originally Posted by NorthernChaosGodWhy would you want to do that again? :|Quote:
Originally Posted by Raistlin
Regardless I'm correct. x = 0 and 26 = 0 . But x != 26 that would be a fallacy.Quote:
Originally Posted by RaistlinBecause the people who refuse to accept it are always entertaining. And math is fun.Quote:
Originally Posted by NorthernChaosGodWhy would you want to do that again? :|Quote:
Originally Posted by Raistlin
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 x2+x = 2x. Subtract 2x from both sides and you get x2-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.Quote:
Originally Posted by Peegeebut I added and mutiplied everything on both sides. Ergo it is valid. x = 0Quote:
Originally Posted by qwertysaur
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 x2-3x = 4. Subtract 4 form both sides to get x2-3x-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 = πr2. The calculus method is possible, but much more time consuming.
oh EoFF :love:Quote:
Originally Posted by qwertysaurIf 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 x2+x = 2x. Subtract 2x from both sides and you get x2-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.Quote:
Originally Posted by Peegeebut I added and mutiplied everything on both sides. Ergo it is valid. x = 0Quote:
Originally Posted by qwertysaur
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 x2-3x = 4. Subtract 4 form both sides to get x2-3x-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 = πr2. The calculus method is possible, but much more time consuming.
ps aren't you aznnnn?
math is for losers.
and bert. asl?Quote:
Originally Posted by Bert
I'm not AZN pg :p
Yet you did math. QEDQuote:
Originally Posted by qwertysaur
Aww, I was hoping you were posting a real equation for me to solve. I miss algebra. ;_;
I consider 0 = 26 a completely valid answer. Just as valid as for example "tuesday".
It is a real equation.Quote:
Originally Posted by ShlupQuack
Fine here's another:
x-7 = x+9 . Solve for x.
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.Quote:
Originally Posted by Raistlin
So x is whatever we determine it to be now, and the past will adapt to our fiction. Christianity 1, atheists 0
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
I already established that x = tuesday. Stop spreading misinformation.
oh btw
which anime is that from?
that's cool, qwerty. I was trolling PGies when I gave him the x=0 proof, but your posts are pretty interesting!
I hate you for spitting in the face of basic algebra, PG.
http://i194.photobucket.com/albums/z...ertNoWay-1.gifQuote:
Originally Posted by Mirage
Quote:
Originally Posted by rubah
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... :(
What do you mean? Please elaborate. I bet that guy isn't even a real teacher, so how would he know?!Quote:
Originally Posted by ShlupQuackImageQuote:
Originally Posted by Mirage
Stephen Colbert knows everything. Especially America things. Like maths.
Okay, okay, guys, I come clean. I am x. :)
I found x!Quote:
Originally Posted by Alive-Man
NorthernChaosGod wins the thread!
What are you 12? asl opQuote:
Originally Posted by Alive-Man
Have a seat over there.Quote:
Originally Posted by PeegeeWhat are you 12? asl opQuote:
Originally Posted by Alive-Man
No. You're not my mommyQuote:
Originally Posted by NorthernChaosGodHave a seat over there.Quote:
Originally Posted by PeegeeWhat are you 12? asl opQuote:
Originally Posted by Alive-Man