State all conditions that must be satisfied by a feasible direction w at the solution indicated to each of the following systems of linear constraints.

(a) 2w1 + 3w3 = 18 1w1 + 1w2 + 2w3 = 14 w1, w2, w3 Ú 0 at w = 10, 2, 62

(b) Same constraints as part

(a) at w = 16, 4, 22.

(c) 1w1 + 1w2 = 10 2w1 - 1w2 Ú 8 1w1 - 8w2 … 1 at w = 16, 42

(d) Same constraints as part

(c) at w = 17, 32.