# Thread: help with simultaneous equations 3 unknownes

1. ## help with simultaneous equations 3 unknownes

hi anyone help me totally stuck on this question thanks first time on forum.
3r-2t=0.2
r+s=2.4
4s-t=7.3

2. That´s what I did:
First eliminate $r$ from the 1st and 2nd equation
$3r-2t=0,2$
$-3r-3s=-7,2$
$-----------$
$-3s-2t=-7,0$

Now eliminate $t$ from this one and the 3rd equation
$3s+2t=7,0$
$8s-2t=14,6$
$-----------$
$11s=21,6$

so $s=21,6/11$ I don´t know if you want to give an approximate of that number, if you want its exact value, it is $s=108/55$
Now you can start the back-substitution in order to get $t$ and $r$

Hope it helped...

3. thanks for that big help cheers