Answer:
Hence the exponent on the variable z is:
-5
Step-by-step explanation:
We have to simplify the expression:
27x^2z/-3x^2z^6
This expression is basically:

As we know that both 3 and 27 are multiples of 3 hence, we divide both the numerator and denominator by 3 to obtain:

Also we know that:

Hence we could write our expression as:

Hence the exponent on the variable z is:
-5