We summarize the algorithm for performing row reduction.
- Step 1
- Determine the left-most column containing a non-zero entry (it exists if the matrix is non-zero).
- Step 2
- If needed, perform a type I operation so that the first non-zero column has a non-zero entry in the first row.
- Step 3
- If needed, perform a type II operation to make that first non-zero entry 1 (the leading 1 in the first row).
- Step 4
- Perform type III operations to make the entries below this leading 1 equal to 0.
- Step 5
- Repeat the previous four steps on the submatrix consisting of all except the first row, until reaching the end of the rows.
- Step 6
- For each row containing a leading 1, proceed upward using type III operations to make zero any entry appearing above a leading 1.
To summarize,
Every system of equations is uniquely represented by its associated augmented
coefficient matrix (ACM), and every ACM results from a unique system of equations,
up to a labeling of the indeterminates. The solution set to the system can be
determined by i) putting the ACM in reduced row echelon form (rref), and ii) reading
off the solution(s) from the resulting matrix. Moreover, the computation of
rref(ACM) can be performed in a systematic fashion, by following the algorithmic
procedure listed above.
Use the row reduction algorithm detailed above to put the following ACMs in reduced row echelon form. Use your answer to find the complete set of solutions to the system of equations the ACM represents.