Question 20 Solve the linear system by Gauss-Jordan elimination procedure. 1 - 2x2 + 3x3 = 1 21 - 3x2 + 5x3 = 0 -1 + 4x2 - 3 = -1 O No solution! O {(-4, -1, 1) } O { (4, 1, -1) } O { (1 + 2t, 1 - t, t) | te R}Question 21 2 pts Suppose we get the following RREF below. Determine the solution set of the system. 1 0 -1 0 1 0 0 0 0 O O O { (1 + a - b, 1 - a, a, b) | a, bER ] O. no solution O { (1, 2, 0) ] O { (1 + a + b, 1 + a, a, b) | a, beR}Question 22 2 pts Suppose we get the following RREF below. Determine the solution set of the system. 1 0 0 0 0 0 0 1 0 0 0 0 1 O. { (0, 1, s, t ) | s, tER } O { (0, 1, 0, t ) | tER} O (0, 1, 1, 1) O no solutionQuestion 23 Which of the following is linear? O In x + ey = 1 O (cos n) x2 + (sin n) y = 1 O 2vx + 1/y = 1 O log x - log x + y = 1Question 24 2 pts Given that matrix A is 3x4, matrix B is 2x3, and matrix C 3x2, D is 3x4, what is the dimension of the CB(A + D)? O 3x4 0 4x3 O 2x3 O. 3x3