There are 4 4-passenger taxis available so that's 4 x 4 = 16 total seats. There are 21 people needing transportation leaving 21 - 16 = 5 who will have to find other transportation.

To raise a term with an exponent to another exponent, retain the base and multiply the exponents:

The ratio of football cards to baseball cards is 9:2 and the ratio of baseball cards to basketball cards is 9:1. To solve this problem, we need the baseball card side of each ratio to be equal so we need to rewrite the ratios in terms of a common number of baseball cards. (Think of this like finding the common denominator when adding fractions.) The ratio of football to baseball cards can also be written as 81:18 and the ratio of baseball cards to basketball cards as 18:2. So, the ratio of football cards to basketball cards is football:baseball, baseball:basketball or 81:18, 18:2 which reduces to 81:2.

To divide terms with radicals, divide the coefficients and radicands separately:

\( \frac{28\sqrt{15}}{4\sqrt{3}} \)
\( \frac{28}{4} \) \( \sqrt{\frac{15}{3}} \)
7 \( \sqrt{5} \)

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

-4c³ x 8c²
(-4 x 8)c^{(3 + 2)}
-32c⁵