Section 1.1: 

Problems: 4 (for 3(a)), 5 (a), 6(h), via Gauss, 7.

Section 2.1:
Problems: 1, 2, 3, 4
 (note that 'lead variables' is also known as 'essential
  variables' that we mentioned in class, see page 14), 
         5(part), 8, 9, 10, 14, 19.

True or false:

If m > n, then the system must be has