Use the given row transformation to change the matrix as indicated.
-$\left[ \begin{array} { r r } - 1 & 4 \ 7 & 0 \end{array} \right] ; 7$ times row 1 added to row 2
A)
$\left[ \begin{array} { r r } - 1 & 4 \ 0 & 28 \end{array} \right]$
B)

$\left[ \begin{array} { r r } - 1 & - 3 \ 0 & 28 \end{array} \right]$
C)
$\left[ \begin{array} { r r } - 7 & 28 \ 7 & 0 \end{array} \right]$
D)
$\left[ \begin{array} { r r } - 1 & 4 \ 7 & 28 \end{array} \right]$

Question

Use the given row transformation to change the matrix as indicated.
-$\left[ \begin{array} { r r } - 1 & 4 \ 7 & 0 \end{array} \right] ; 7$ times row 1 added to row 2
A)
$\left[ \begin{array} { r r } - 1 & 4 \ 0 & 28 \end{array} \right]$
B)

$\left[ \begin{array} { r r } - 1 & - 3 \ 0 & 28 \end{array} \right]$
C)
$\left[ \begin{array} { r r } - 7 & 28 \ 7 & 0 \end{array} \right]$
D)
$\left[ \begin{array} { r r } - 1 & 4 \ 7 & 28 \end{array} \right]$

Quizplus · Accepted Answer

To perform the row operation, multiply each element of row 1 by 7 and add it to the corresponding element of row 2. For the first element: $7 \times (-1) + 7 = 0$. For the second element: $7 \times 4 + 0 = 28$. This results in the new row 2 being [0, 28], making option A correct.

Use the Given Row Transformation to Change the Matrix as Indicated