Respuesta :

The easiest way to solve this is to make a proportion problem
Here is what we have so far...
[tex] \frac{x}{z} [/tex] 
[tex] \frac{x(12)}{z(36)} [/tex] = [tex] \frac{x(19)}{z} [/tex]
cross multiply 
12z = 36 × 19
12z = 684
z = 57