could someone go through the steps for me for giving x,y,z in terms of m,my method is really long and wrong.
4x+y+7z=12
3x+2y+5z=m
8x+5y+13z=0
thnx alot
Hello,
You can use matrices..
$\displaystyle \begin{pmatrix} 4 & 1 & 7 \\ 3 & 2 & 5 \\ 8 & 5 & 13 \end{pmatrix} \begin{pmatrix} x \\ y \\ z \end{pmatrix}=\begin{pmatrix} 12 \\ m \\ 0 \end{pmatrix}$
And act on the first matrix (3x3)
Otherwise... it's the same method as above :
(3)-2(1) will annulate x. --> expression in terms of y and z.
(2)-2(1) will annulate y. --> expression in terms of x and z (and m).
5(1)-7(2) will annulate z. --> expression in terms of x and y (and m).
etc