Determine whether the matrix is in echelon form, reduced echelon form, or neither.
-$$\left[ \begin{array} { r r r r }
1 & 2 & 5 & - 7 \
0 & 1 & - 4 & 9 \
0 & 0 & 1 & 2
\end{array} \right]$$
A)Reduced echelon form
B)Echelon form
C)Neither

Question

Determine whether the matrix is in echelon form, reduced echelon form, or neither.
-$$\left[ \begin{array} { r r r r } 
1 & 2 & 5 & - 7 \
0 & 1 & - 4 & 9 \
0 & 0 & 1 & 2
\end{array} \right]$$
A)Reduced echelon form
B)Echelon form
C)Neither

Quizplus · Accepted Answer

The matrix is in echelon form because each leading entry (first nonzero number from the left in a row) is to the right of the leading entry in the row above it, and all entries in a column below a leading entry are zeros. It is not in reduced echelon form because not all leading entries are 1 (though they are in this case) and not all leading 1s have only zeros above them in their column.

Determine Whether the Matrix Is in Echelon Form, Reduced Echelon [125−701−490012]\left[ \begin{array} { r r r r } 1 & 2 & 5 & - 7 \\0 & 1 & - 4 & 9 \\0 & 0 & 1 & 2\end{array} \right]​100​210​5−41​−792​​

Determine Whether the Matrix Is in Echelon Form, Reduced Echelon $\left[ \begin{array} { r r r r } 1 & 2 & 5 & - 7 \\0 & 1 & - 4 & 9 \\0 & 0 & 1 & 2\end{array} \right]$