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:

-3y⁴ x 7y²
(-3 x 7)y^{(4 + 2)}
-21y⁶

To subtract these radicals together their radicands must be the same:

5\( \sqrt{175} \) - 9\( \sqrt{7} \)
5\( \sqrt{25 \times 7} \) - 9\( \sqrt{7} \)
5\( \sqrt{5^2 \times 7} \) - 9\( \sqrt{7} \)
(5)(5)\( \sqrt{7} \) - 9\( \sqrt{7} \)
25\( \sqrt{7} \) - 9\( \sqrt{7} \)

Now that the radicands are identical, you can subtract them:

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 100 meters to kilometers, divide the distance by 1000 to get 0.1km then add the remaining distances:

total distance = swim + bike + run
total distance = 0.1km + 30.7km + 9.3km
total distance = 40.1km

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

Solving for distance:

distance = \( \text{speed} \times \text{time} \)
distance = \( 60mph \times 7h \)
420 miles

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

Solving for time:

time = \( \frac{\text{distance}}{\text{speed}} \)
time = \( \frac{300mi}{60mph} \)
5 hours