Question

I need help with this please

Answer 1

Multiply row 1 by 1/7

The resulting matrix is

`\begin{pmatrix}1&-(4)/(7)&(8)/(7)\\ -12&7&-13\end{pmatrix}`

Explanation:

Original matrix is

`\begin{pmatrix}7&-4&8\\ -12&7&-13\end{pmatrix}`

Multiplying any one row by a nonzero scalar is a valid matrix operation. This will not affect the final solution of the matrix

So all we have to do is to multiply row 1 by 1/7 and you get a 1 in row 1, column 1

`R_1 * (1)/(7) \longrightarrow \begin{pmatrix}1&-(4)/(7)&(8)/(7)\\ -12&7&-13\end{pmatrix}`