solving systems with substitution?

Question

nincompoop · Answer

yes, you can

solomonzelman · Answer

elimination is mostly better.

anonymous · Answer

oops, I meant to put the link to the problem: https://31.media.tumblr.com/0c6d5f3bb262275c0bf252984770fd89/tumblr_inline_ni57gs28ib1qh9byg.png

anonymous · Answer

I prefer elimination, but this one calls for substitution specifically, and I just can't figure out how to do this problem :/

solomonzelman · Answer

you are given in the third equation that x is same as -3z.
So you can substitute -3z instead x into every other (1st and 2nd) equations.

solomonzelman · Answer

$\large\color{blue}{ 3x+y-22=22 }$ 
$\large\color{blue}{ x+5y+z=4 }$ 

substitution,

$\large\color{blue}{ 3(-3z)+y-22=22 }$ 
$\large\color{blue}{ (-3z)+5y+z=4 }$

solomonzelman · Answer

is my latex working for u, because it isn't for me...

anonymous · Answer

I can't solve down very far, I just get y=11z+22 for the top equation and a complicated fraction for the second

anonymous · Answer

@SolomonZelman any other ideas?