|
#1 Posted 7:52pm 29-01-10 Easy one for olympiad aspiratorsIf 4x-y is divisible by 3, prove that 4x[p]2[/p]+7xy-2y[p]2[/p] is divisible by 9.
Fermat |
|
#2 Posted 09:38am 30-01-10 Re: Easy one for olympiad aspiratorsNot related but aspirators is not the word you are looking for. Since I have some link to the medical field, I am familiar with http://en.wikipedia.org/wiki/Aspirator Should be aspirants
Edited on 0:39pm 30-01-10 |
|
#3 Posted 10:37am 30-01-10 Re: Easy one for olympiad aspirators4x-y=3m y=4x-3m put y=4x-3m in 4x[p]2[/p]+7xy-2y[p]2[/p] u will get 4x[p]2[/p]+7xy-2y[p]2[/p] as 9m(3x-2m) hence divisible by 9 [im]http://www.mathlinks.ro/images/smiles/wink.gif[/im]
Dont Mess With Che~! |
|
#4 Posted 11:14am 30-01-10 Re: Easy one for olympiad aspirators4x[p]2[/p]+7xy-2y[p]2[/p]=(4x-y)(x+2y) So we only need to prove that x+2y = (4x-y)-3(x-y) is divisible by 3 which is obvious. |
