Thread: simultaneous equations arrgh

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..



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