Question 208616
 -12xz/(3y)+12z (squared)/x
x=-4 y=-2 z=1\2
----------
{{{-12xz/3y + 12z^2/x}}}
If that's not what you meant, you need to add parentheses to make it clear.
= {{{-4xz/y + 12z^2/x}}}
= (-4*-4*(1/2)/(-2) + 12*(1/4)/(-4)
= 8/(-2) + 3/(-4)
= 16/(-4) + 3/(-4)
= 19/(-4)
= -19/4