2. For A = 1 2 3 4 56 789 I1 +22 +x4 = 3 = 4 I2 +13 1 +2x +3 +4 =8 b) and B = a) -A; b) 3A; c) A + 2B; d) AT; e) BT; f) AB; g) BA. 3. Use the Gauss-Jordan method to determine whether each of the following linear systems has no solution, a unique solution, or infinite number of solutions. Indicate the solutions (if any exists). a) = 1 = 3 = 4 1 2 0 -1 1 2 find: Z1 +22 2x1 +22 3x +22 c) 221 -I2 +3 +4 = 6 = 4 21 +2 +3 4. Represent graphically the linear equations and solutions (if any) of question 3(b).