Respuesta :

add 8 to both sides
5z = 40
divide both sides with 5
z = 8
Z=8 

The reason i know this is:
5z-8=32     add 8 to both sides
5z - 8 = 32
    + 8    +8 (the -8+ 8 get taken off.)
So you have left 
5z=40
divide
5z       =     40
----            ------
5                  5
the 5's get crossed out 
and divide 40 by 5 and you'll get 8 :)