(parts i-v of this problem are to be done by hand using the principles of linear algebra.) for the given system of equations, 2x1 + x2 = 1 x1 − 2x2 = −12 i. (1 pt) rewrite the system in the format = where x and b are column vectors. ii. (1 pt) rewrite the system in the format = where y and d are row vectors. iii. (2 pts) show that matrices a and c are invertible. iv. (2 points) find the inverses a-1 and c-1. v. (2 pts) solve the system formatted in [i] for and the system formatted in [ii] for i. e., determine x1and x2. vi. (2 pts) solve the system formatted in [i] for and the system formatted in [ii] for using matlab and compare your results with the results of part [v].