Okay so I don't know how to do this question from my math homework
So can you please help me (: it would be a plus if you could show me how to do it too!
Well this is the question
"Elimination with systems of three equations"
10x+2y+z=885
5x+4y+z=865
9x+6y+z=1410



[btw I got x=113,y=282.5,z=-830]
but i'm pretty sure i'm wrong