Re: Solving multiple equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg125555] Re: Solving multiple equations*From*: Peter Pein <petsie at dordos.net>*Date*: Sun, 18 Mar 2012 02:47:23 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jk1g20$51v$1@smc.vnet.net>

Am 17.03.2012 08:55, schrieb Themis Matsoukas: > I have two set of equations, one in the form, > > eq1 = ({0.15, 0.85, X1} == {X3, X2 + X4, X5}) > > and the other in the form > > eq2={1. X1 == 9/5, X4/(X3 + X4 + X5)==1/3} > > Solve understands both Solve[eq1] and Solve[eq2] but if I want to solve the two sets simultaneously, what is the best way to combine eq1 and eq2 into a single list of equations, either of the form of eq1 or of eq2, that Solve can understand? > > Themis > Hi Themis, to avoid the mixture of exact/inexact numbers and the equations with scalars/lists, try: eq1 = {0.15, 0.85, X1} == {X3, X2 + X4, X5}; eq2 = {1.*X1 == 9/5, X4/(X3 + X4 + X5) == 1/3}; Solve[Rationalize @ Join[Thread[eq1], eq2]]] Peter