Hello,

You can use matrices..

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