When solving indefinite equations A*x=B, I have already know the range of Some values about x , how to set this boundary condition

such as A=[21 32 43 54; 3 4 3 5; 2 3 4 5;2 3 2 1;3 2 1 3;3 4 2 3], i already know x1,x2 and x3<2, how can i set up a boundary condition, before i use x=pinv(A)*B to solve it.