To add these distances, they must share the same unit so first you need to first convert the swim distance from meters (m) to kilometers (km) before adding it to the bike and run distances which are already in km. To convert 500 meters to kilometers, divide the distance by 1000 to get 0.5km then add the remaining distances:

total distance = swim + bike + run
total distance = 0.5km + 40.9km + 12.5km
total distance = 53.9km

Average speed in miles per hour is the number of miles traveled divided by the number of hours:

The number of students taking German or Spanish is 11 + 5 = 16. Of that group of 16, 4 are taking both languages so they've been counted twice (once in the German group and once in the Spanish group). Subtracting them out leaves 16 - 4 = 12 who are taking at least one language. 25 - 12 = 13 students who are not taking either language.

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:

\( \frac{-9z^8}{9z^2} \)
\( \frac{-9}{9} \) z^{(8 - 2)}
-z⁶

To fill a 8 gallon tank exactly halfway you'll need 4 gallons of fuel. Each fuel can holds 1 gallons so:

cans = \( \frac{4 \text{ gallons}}{1 \text{ gallons}} \) = 4