Sami,
Glad it helped.
The solutions are in the form of rules (i.e. a->5.3). Rules are setup for use with the Replace[] function. The best way to use this is to do what you are doing now and get your solution in the form of a list of Rules:
sol = Solve[...]
Then apply the solution to some expression
numbersolution = expr /. sol
Now numbersolution will be expr with all the variables replaced with numbers.
Another option is to define the variables globally (although I really do not like to do this -- I like to control when I substitute variables for numbers)
sol /. Rule->Set
This causes Mathematica to change the rules to a bunch of immediate assignments using Set[] (the single equal is its shortcut) -- not to be confused with double equal which is Equal (==). Set[] globally defines the variables. Again, this is usually not my first choice but if you just want them to become numerical in some circumstances it can be helpful.
Regards,
Neil
