First you combine like terms together:
6z + 3 -4z =9
(6-4=2)
Now put everything back in its place:
2z + 3= 9
To get the variable (z) by itself, you have to subtract 3 from both sides of the equal sign:
2z + 3 = 9
-3 -3
Now it should be:
2z = 6
Then the final step is to divide by 2 on both sides of the equal sign.
2z = 6
2 2
Your final answer after this should be:
z = 3
