2. 136.130: Test #2

20 minutes

Name:_____________________ Student Number: _______

1. Suppose and . Find

(a)

(b) 

2. Which of the following matrices are in Row Reduced Echelon form, which are

in Echelon form (but not in RRE form) and which are neither? Brieffly justify your answers.

, , , .

A is neither in RRE form nor in E form (non-zero entry below a leading 1)

B is in RRE form

C is in E from.

D is neither: zero row not at the bottom.

3. Solve the following system using Gauss-Jordan elimination.

The augmented matrix is , We row reduced it to get RRE form . The associate system is

and with we get as the general solution.