Answer :

3z-4=6z-17
-3z-4=-17 (subtracted the 6z from both sides)
-3z=-13 (added the 4 to both sides)
z=[tex] \frac{-13}{-3z} [/tex] (divided both sides by -3z)
z=[tex] \frac{13}{3} [/tex]
3z - 4 = 6z - 17.               First try to take all the zs to one side of the equation
                                      preferrably to the left. And the sign of any expression
                                      changes on crossing the equality sign.

3z-6z = -17+4
-3z     =  +4-17
-3z     =   - 13.                       Divide both sides by -3.
 -3z/-3   =  -13/-3
 
z = 13/3.