I think this should be easy to numerically solve in Mathematica, but for some reason I'm not finding the correct way to do it.
I basically want to solve these simyltaneous equiations:
NSolve[
{
-(0.7)*w + (0.3)*y + (0.4)*z == 0,
-(0.6)*x + (0.2)*y + (0.1)*z == 0,
(0.5)*w + (0.3)*x - y == 0,
(0.2)*w + (0.3)*x + (0.5)*y - (0.5)*z == 0, \
w + x + y + z == 1
},
{z , w , x , y}]
This is what i see:

NSolveinstead of nslove - capitalization matters. – Vitaliy Kaurov Oct 4 '12 at 7:13