Question

-1 -1 | -12
-3 2 | 32
How would you put this into row echelon form ?

Answer 1

`\left[\begin{array}c-1&-1&-12\\-3&2&32\end{array}\right]`

Multiply through row 1 by -1:

`\left[\begin{array}c1&1&12\\-3&2&32\end{array}\right]`

Add 3(row 1) to row 3:

`\left[\begin{array}cc1&1&12\\0&5&68\end{array}\right]`

Multiply through row 2 by 1/5:

`\left[\begin{array}cc1&1&12\\0&1&\frac{68}5\end{array}\right]`

Add -1(row 2) to row 1:

`\left[\begin{array}cc1&0&-\frac85\\&&\\0&1&\frac{68}5\end{array}\right]`