Question

Matrix help. *question below* Will give medal

Answer 1

So I've done part a to this question. But I'm not sure how to tackle part b. Can I have some help please?

Answer 2

This is what we call the Gauss-jordan method. You can also use Kramer's method as well, but that futher more.
We will take the coeficents and we write them down in a matrix, just by that order:
\[\left[\begin{matrix} 1& 1&1&1 \\ 2 & 3&3&3\\ 1 & 2&2& \alpha\end{matrix}\right]\]
And that is the augmented matrix.

Answer 3

Yes, I ended up with that for the augmented matrix. I'm clueless as to how to go about part b

Answer 4

What you want in part b, in order to get it to row-echelon form, you have to operate the rows and colums in order to get the matrix in a form like this:
\[\left[\begin{matrix}1 & 0 &0&a \\ 0 & 1&0&b\\ 0 & 0&1&c\end{matrix}\right]\]
with that, I mean you take the numbers that represent the variables, and then make that diagonal and try to get a row of 1s and the rest zeros.

Answer 5

the strategy here, is to create the zero's by operating the rows and colums.

Answer 6

I've tried multiplying row 2 by -1 and multiplying row 3 by 2 but got stuck after...

Answer 7

Then you have to combine rows 2 and 3 to get it into echelon form.
Is my notation or steps confusing? :o