Answer:
C
Explanation:
If you add the first equation up you get 2z+6 by combining like terms
if you see A a is equal to 3z+6 so a doesn’t work
If you look at B b is equal to z+12 so b doesn’t work
finally C if you distibute it out you get 2(z)+2(3) which equal 2z+6 which works
C