You can put this solution on YOUR website! To solve any equation, you can use PEMDAS (Order of Operations) backwards. First get rid of any subtraction and addition.
Add 19 to both sides. 3z-19+19=173+19 --> 3z=192
Then get rid of any multiplication and division.
Divide both sides by 3. 3z/3=192/3 --> z=64
Finally, plug your answer back in to make sure you did it right.
3(64)-19=192-19=173 We have the right answer! :-)