# Eliminate X And Y

### #1

Posted 20 December 2009 - 07:16 AM

### #2

Posted 20 December 2009 - 05:40 PM

This is one of the many many trick problems that people discover by playing with their calculators. I am not familiar with the casio menu synthex but on a TI-89 or Voyage 200 you simply enter solve(1/x+1/y=1 and x+y=a and y/x=m, {y}) then three new equations will be returned one of which is a=(m^2+2m+1)/m and that is your answer but in a different form. To change it into the form you have, just multiply both sides by m and you have am=m^2+2m+1 and then use factor to turn m^2+2m+1 into (m+1)^2 and you have the form of the answer you show which is (m+1)^2=ma. There is no limit to the number of puzzles of this type that one can come up, and solving one usually leads to requests to solve the next one and the one after that and so on, until you are exhausted. So if someone tricked you into working on this problem, show them the answer and quit, which I will now do.Hi there, can someone tell me how to work this problem on classpad. It goes like this I have to eliminate x and y the these equation 1/x+1/y=1,x+y=a,y/x=m. It said that a is not equal 0 and to find the relationship between a and m. I already know that the answer is (m+1)^2=ma I just want to know how to do it on Classpad. cam someone please help me with this. Thank you in advance.

### #3

Posted 21 December 2009 - 11:24 PM

This is one of the many many trick problems that people discover by playing with their calculators. I am not familiar with the casio menu synthex but on a TI-89 or Voyage 200 you simply enter solve(1/x+1/y=1 and x+y=a and y/x=m, {y}) then three new equations will be returned one of which is a=(m^2+2m+1)/m and that is your answer but in a different form. To change it into the form you have, just multiply both sides by m and you have am=m^2+2m+1 and then use factor to turn m^2+2m+1 into (m+1)^2 and you have the form of the answer you show which is (m+1)^2=ma. There is no limit to the number of puzzles of this type that one can come up, and solving one usually leads to requests to solve the next one and the one after that and so on, until you are exhausted. So if someone tricked you into working on this problem, show them the answer and quit, which I will now do.

Hi, thank you very much for your help. I was able to convert the advise that you gave me to Classpad's function. Once again thank you very much.

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