Let L : R2→R 2 be a LT and let S = {v1, v2} be a basis for R2 , where v1= (1, -1) and v2 = (4, -2) . Suppose that L(v1) = (-2, 1) and L(v2) = (4, -1) . Find L(v) when v = (-1, 3) using RREF.