Re: What is causing this error message?

*To*: mathgroup at smc.vnet.net*Subject*: [mg57559] Re: [mg57537] What is causing this error message?*From*: "Ingolf Dahl" <ingolf.dahl at telia.com>*Date*: Wed, 1 Jun 2005 06:01:49 -0400 (EDT)*Reply-to*: <ingolf.dahl at telia.com>*Sender*: owner-wri-mathgroup at wolfram.com

By using the Set (=) sign you are trying to set the value of (x^3y + xy - 10) to zero. Mathematica sees this as an attempt to change the rules for addition, and protests consequently. You should use the Equal sign (==) in equations. Do not forget to put multiplication signs or spaces in relevant places, where multiplication is intended! Is this what you mean? NSolve[{x^3*y + x*y - 10 == 0, x*y^2 - x*y + 6 == 0}, {x, y}] Good luck! Ingolf Dahl Sweden -----Original Message----- From: Bookreader [mailto:bookreader127 at yahoo.com] To: mathgroup at smc.vnet.net Subject: [mg57559] [mg57537] What is causing this error message? NSolve[{x^3y + xy - 10 = 0, xy^2 - xy + 6 = 0}, {x, y}] Set::write: Tag Plus in -10 + x y + x^3 y is Protected. More. Please tell me how to correct this. Thanks.