If 7x+2y-6z =12 and if x y and z are positive then what is the value of 2+z/7x+2y

We know that : 7 x + 2 y - 6 z = 12
Therefore:
7 x + 2 y = 12 + 6 z
We will substitute it to:
( 2  + z ) / ( 7 x + 2 ) =
= ( 2 + z ) / ( 12 + 6 z ) =
= ( 2 + z ) / 6 * ( 2 + z ) =
= 1 / 6
The value is 1 / 6.

Is there any commas or anything