To divide terms with exponents, the base of both exponents must be the same. In this case they are so divide the coefficients and subtract the exponents:

\( \frac{-9z^9}{4z^4} \)
\( \frac{-9}{4} \) z^{(9 - 4)}
-2\(\frac{1}{4}\)z⁵

A factor is a positive integer that divides evenly into a given number. For example, the factors of 8 are 1, 2, 4, and 8.

In order to find how many additional workers are needed to staff the extra crews you first need to calculate how many workers are on a crew. There are 16 workers at the company now and that's enough to staff 4 crews so there are \( \frac{16}{4} \) = 4 workers on a crew. 8 crews are needed for the busy season which, at 4 workers per crew, means that the roofing company will need 8 x 4 = 32 total workers to staff the crews during the busy season. The company already employs 16 workers so they need to add 32 - 16 = 16 new staff for the busy season.

There are 3 4-passenger taxis available so that's 3 x 4 = 12 total seats. There are 17 people needing transportation leaving 17 - 12 = 5 who will have to find other transportation.

To multiply fractions, multiply the numerators together and then multiply the denominators together:

\( \frac{2}{5} \) x \( \frac{3}{9} \) = \( \frac{2 x 3}{5 x 9} \) = \( \frac{6}{45} \) = \(\frac{2}{15}\)