If the following system has infinitely many solutions,

$\displaystyle -4x-5y-6z=6$

$\displaystyle -5x+7y+3z=7$

$\displaystyle 14x-9y+hz=k$

then k=?, h=?

I've been working on this and can't figure it out, could someone solve it and show me the answer as well as how they got to the answer? Thanks!