My Math Forum two variable equation

 Linear Algebra Linear Algebra Math Forum

 January 19th, 2017, 05:24 AM #1 Member   Joined: Jan 2012 Posts: 57 Thanks: 0 two variable equation Hi, Is there any systematic way to solve equations like this $\displaystyle xy^{2}+y-4y+2=0$ I know the answer is x=y=1 thanks
 January 19th, 2017, 05:45 AM #2 Global Moderator     Joined: Oct 2008 From: London, Ontario, Canada - The Forest City Posts: 7,814 Thanks: 1046 Math Focus: Elementary mathematics and beyond If you write it as a quadratic, you get $$y=\frac{3\pm\sqrt{9-8x}}{2x}$$ There are solutions other than the one you mentioned. In fact, for real x and y, there are solutions wherever $9\ge8x$. x = 1 and y = 2 is another set of solutions in positive integers. Thanks from mhhojati and topsquark
January 19th, 2017, 09:33 AM   #3
Math Team

Joined: Oct 2011

Posts: 12,594
Thanks: 843

Quote:
 Originally Posted by mhhojati xy^2+y-4y+2=0
Any reason you did not post your equation this way:
xy^2 - 3y + 2 = 0 ?

 January 20th, 2017, 04:41 AM #4 Member   Joined: Jan 2012 Posts: 57 Thanks: 0 no that equation was part of the solution of another question and I forgot to trim it

 Tags equation, variable

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post Bencz Algebra 4 May 4th, 2013 04:14 PM doron Algebra 2 October 16th, 2012 07:39 AM dpwheelwright Algebra 5 August 19th, 2012 12:48 AM mtayab1994 Algebra 1 May 18th, 2012 03:49 AM doron Abstract Algebra 0 December 31st, 1969 04:00 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top