Jesse Use Mathematica to solve it Linear algebra Exercises 1. a. Write a matrix with 4 rows and 3 columns of your choice. 2. Write 3 rows vectors of your choice and compute their sum. 3. Solve the following system using the 3 ways explained above b. Write a 3x3 matrix and display the second row, and each of its three elements 2a-b+7c 16 3a-3b +9c = 19. a-2b +c = 0 Answer: (-7/3, 1/3, 3) Solution 1 a ).