Early homework for Wednesday, September 4

If you submitted these by 5:00 pm Wednesday, you don't have to turn in problems 5, 11, or 20 from section 1.1 or problems 2c or 4 from section 1.2 in section on Thursday.

Solutions to these problems are here:.txt,.ps,.pdf

Question 1:
Consider the system of equations:

x1+3x2+3x3-2x4=13
-2x1+x2-x3+2x4=-2
-x1-4x2-2x4=17
-x1-x2-4x3+5x4=34

Write down the augmented matrix for this system.
(Note: You do not have to solve the system.)
Question 2:
Let M=
14-3-3-27
15-1-4-22
-315-426
.
Reduce M to echelon form. Label every step in the reduction.
(Note:It's not necessary to continue the reduction until M reaches reduced echelon form.)

Question 3:
Suppose that M is the augmented matrix for some linear system. How many solutions does it have? Justify your answer. (One or two sentences should suffice.)