Related Materials:
http://math.mit.edu/~gs/linearalgebra/linearalgebra5_1-3.pdf
https://www.youtube.com/watch?v=kjBOesZCoqc&index=1&list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab
Homework:
23 and 28 from section 1.2
4 and 13 from section 1.3
https://ocw.mit.edu/courses/mathematics/18-06-linear-algebra-spring-2010/assignments/MIT18_06S10_pset1_s10_soln.pdf