matrix Ax=b

I'm trying to solve matrix Ax=b, in x i have const. variables and in b also. for example:

 A=  2    -1    -1     0    -1     1
    -1     1     0     0     1    -1
    -1     0     1     0     0     0
     0     0     0     1     0    -1
    -1     1     0     0     1    -1
     1    -1     0    -1    -1     2
x= [0 0 v2/tand(30) v2 u3 0]

b= [r1x r1y r2y r2y*tand(30) 100 r3y]

what is the way for solving this equation with 6 const. variables? Thank you very much for your help, Very appreciate this!

[Star Strider]

What variables do you know (have numeric values for) and what unknown variables are you solving for?

[Eli]

v2 r1x r1y r2y r3y u3 6 unknown variables and 6 equations, so it can be solved. the problem is how to do it in matlab:) thank you

[Star Strider]

What variables do you know (have numeric values for) and what unknown variables are you solving for?