Answer:
z / 3 = 2z / 6
1 / 2 = 3 / 6
( 3 + 2z ) / 6 = 5 /2
5 / 2 = 15 / 6
3 + 2z / 6 = 15 / 6
3 + 2z = 15
2z = 12
z = 6
