G, EB, etc are not guess values. Those are defined constants, and should be above the solve block. At the top of the solve block you need guess values for I1, I2, and I3 (it will iterate from those values to the solution).
So is there anyway i can solve those equations with out the use of guess values?
You only have three independent equations - you can get rid of your first and fourth. Because the system is linear you can solve it without guessing anything - see attached (includes solutions with and without initial guesses)
Okay thanks for the help. I do not quit understand the way you use the matrix way. It has been some time since i have used mathcad last but what i´m really looking for is something like (Given, Find) like in mathcad 13
