Simple..
there is a major difference between 6z and [tex] z^{6} [/tex]
6z means: 6 times z
and
[tex] z^{6} [/tex] means: z to the power of 6(z*z*z*z*z*z)
An example...
make z=2...plug n chug..
6z----> 6(2)=12
and
[tex] z^{6} [/tex]--->[tex] 2^{6} [/tex]=64
As you can see..there is a major difference.
Thus, your answer.
