To obtain an obvious basic solution to (3), we choose s1 , s2 , s3 , and P as basic variables (since each occurs in exactly one equation and no two appear in the same equation). This leaves x1 and x2 (each occurring in more than one equation) as nonbasic variables. Setting the nonbassic variables equal to zero, a basic feasible solution to (3) can be obtained by inspection (thus the name “obvious basic feasible solution”):