Perform the indicated elementary row operations.
-$\begin{array} { l }
(9)\mathrm { R } _ { 1 } + \mathrm { R } _ { 2 } \
{ \left[ \begin{array} { r r }
8 & 5 \
- 8 & - 1
\end{array} \right] }
\end{array}$

A)$\left[\begin{array}{rr}
-64 & -4 \
-8 & -1
\end{array}\right]$

B)$\left[\begin{array}{rr}
8 & 5 \
64 & 44
\end{array}\right]$

C)$\left[\begin{array}{rr}
72 & 45 \
-8 & -1
\end{array}\right]$

D)$\left[\begin{array}{rr}
8 & 77 \
-8 & -73
\end{array}\right]$

Question

Perform the indicated elementary row operations.
-$\begin{array} { l } 
(9)\mathrm { R } _ { 1 } + \mathrm { R } _ { 2 } \
{ \left[ \begin{array} { r r } 
8 & 5 \
- 8 & - 1
\end{array} \right] }
\end{array}$

A)$\left[\begin{array}{rr}
-64 & -4 \
-8 & -1
\end{array}\right]$

B)$\left[\begin{array}{rr}
8 & 5 \
64 & 44
\end{array}\right]$

C)$\left[\begin{array}{rr}
72 & 45 \
-8 & -1
\end{array}\right]$

D)$\left[\begin{array}{rr}
8 & 77 \
-8 & -73
\end{array}\right]$

Quizplus · Accepted Answer

Adding row 1 to row 2 involves adding the elements of row 1 to the corresponding elements of row 2. For the given matrix, this results in the new row 2 being $8 + (-8) = 0$ for the first column, and $5 + (-1) = 4$ for the second column. The correct operation actually yields a matrix where the first row remains unchanged and the second row is the sum of the first and second rows. The correct answer is $\left[\begin{array}{rr} 8 & 5 \ 0 & 4 \end{array}\right]$, which is not listed among the options, indicating a mistake in the explanation. The correct operation was misunderstood in the explanation provided.

Perform the Indicated Elementary Row Operations A) [−64−4−8−1]\left[\begin{array}{rr}-64 & -4 \\-8 & -1\end{array}\right][−64−8​−4−1​]

Perform the Indicated Elementary Row Operations A) $\left[\begin{array}{rr}-64 & -4 \\-8 & -1\end{array}\right]$