Find the solution set of the system of linear equations represented by the augmented matrix. (If there is no solution, enter NO SOLUTION. If the system has an infinite number of solutions, set x_4 = t and solve for x_1, x_2, and x_3 in terms of t.) [1 2 0 1 5 0 1 2 1 4 0 0 1 2 3 0 0 0 1 5] (x_1, x_2, x_3, x_4) - ()