Answer
a. yes
b. yes
c. $\left\{\begin{array}{l}
x+3y-w=0\\
z+2w=0\\
0=1\\
0=0
\end{array}\right.$
Work Step by Step
A matrix is in row-echelon form if its entries satisfy the following:
1. The first nonzero entry in each row (the leading entry) is the number 1.
2. The leading entry of each row is to the right of the leading entry in the row above it.
3. All rows consisting entirely of zeros are at the bottom of the matrix.
If the matrix also satisfies the following condition,
4. If a column contains a leading entry, then every other entry in that column is a $0$.
it is in reduced row-echelon form.
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a. Variables: x,y,z,w. Leading: x and z.
1. is satisfied,
2. is satisfied,
3. is satisfied
b.
4. is satisfied
c. The last column is the constant column.
The equations represented:
$\left\{\begin{array}{l}
x+3y-w=0\\
z+2w=0\\
0=1\\
0=0
\end{array}\right.$
