Linear systems

 

In Maple

For comparison with other CAS choose from: Axiom Derive Macsyma Mathematica Reduce

inputs outputs

    solve( {2*x1 + x2 + 3*x3 - 9 = 0,  x1 - 2*x2 + x3 + 2 = 0,      \
            3*x1 + 2*x2 + 2*x3 - 7 = 0}, {x1, x2, x3} );

                              {x1 = -1, x2 = 2, x3 = 3}