Answer:
The expression 3z^2 - 27 can be simplified by factoring out the greatest common factor (GCF), which is 3:
3z^2 - 27 = 3(z^2 - 9)
Now, we can simplify the expression further by recognizing that the term inside the parentheses is the difference of squares, which can be factored as:
z^2 - 9 = (z + 3)(z - 3)
Substituting this back into our original expression, we get:
3z^2 - 27 = 3(z^2 - 9) = 3(z + 3)(z - 3)
Therefore, the simplified form of the expression 3z^2 - 27 is 3(z + 3)(z - 3).