1. If B-C = 0, what reasoning is used to show that B=C?
   a) additive inverse
   b) additive identity
   c) associativity
   d) exactly 2 from above
   e) all of a, b, c
   
   
   
   
2. If the product of two matrices equals the 0 matrix, then
   a) one of the matrices has to equal the 0 matrix
   b) both matrices have to equal the 0 matrix
   c) neither a nor b
   
   
   
   
3. If A is a square matrix and Ax=b has infinite solutions for 1 vector b, then
   a) A is not invertible and I have a good reason why
   b) A is not invertible but I am unsure of why
   c) A is invertible but I am unsure of why
   d) A is invertible and I have a good reason why
   e) There is no way to tell whether A is invertible without more information
   
   
   
   
4. If A is a matrix that is NOT square and Ax=b has infinite solutions for 1 vector b, then which best describes A:
   a) Ax=b must always have infinite solutions
   b) Ax=b can have 0, 1 or infinite solutions
   c) Ax=b can have 0 or infinite solutions
   d) Ax=b can have 1 or infinite solutions
   
   
   
   
5. Let T: x ---> Ax be given as a linear transformation arising from a square 2x2 matrix A. Assume that the set of all outputs b (from Ax=b) is a line. What can we deduce?
   a) The columns of A do not span R² and I can think of an example
   b) The columns of A do not span R² and I can not think of an example
   c) A is onto R²
   d) The columns of A do not span R² and A is onto R²
   e) None of the above statements are true