I'm a bit stuck with the idea of eliminating variables from a set of simultaneous equations . . . for example, suppose you have two equations (with more than 3 variables), could you, in principle, reduce it to one equation with one variable less? And if you had three equations with lets say 4 variables, could you, in principle, reduce them to 2 equations with 3 variables, and them in turn to one equation with 2 variables? So in general, if you have m equations and n variables, with n>m, then can you, in principle, eliminate m-1 variables, so that you end up with a single equation with n-(m-1) variables? Is this correct? (I say in principle because I suppose you need to assume all the equations are independent and stuff like that:P).