Respuesta :

Z-12=6

you take the 12 and add it to both sides making it look like:
z-12+12=6+12
which also looks like
z-0=6+12

z-0 = z

so now you have
z=6+12

6+12 = 18

SO Z=18!!!

your answer is 18
c. 18 i think is the correct answer