@Carl Love This seems to have done the trick. The intent was definitely not to completely remove the indexed variables, but the endpoint is supposedly going to have to have (1-V) terms in the denominator, which is where this looks like it's going now. Thanks a ton for the help :)

I figure having something to look at would be helpful, so here's one of the equations I have in the matrix:

(v23*v32-1)*E1/(v12*v23*v31+v13*v21*v32+v12*v21+v13*v31+v23*v32-1)

And here's what I need it to substitute:

V := 2*v13*v21*v32+v12*v21+v13*v31+v23*v32

more or less, I just need everything to be put in terms of V so I can drop all the subscripts.