
When variables with exponents are divided by each other, you subtract the exponents.
For example:


Answer:
450 minutes
Step-by-step explanation:
Given
w = 45000 - 100t
Required
Determine how long it'll take to empty the pool
Being empty means there's no water in the pool.
So, we have to set w to 0 to get the value of t
i.e w = 0
Substitute 0 for w in w = 45000 - 100t
0 = 45000 - 100t
Collect Like Terms
100t = 45000
Divide through by 100.
t = 450
Hence, it'll take 450 minutes to empty the pool
The sister catches up Jeff after 2 hours
Step-by-step explanation:
We can write Jeff's position and his sister position at time t using the following expressions:
- Jeff position:

where:
7 is the initial position of Jeff when his sister sarts chasing him
2.5 is Jeff's velocity (in miles/hour), so its position increases by 2.5 miles for each hour
t is the time measured in hours
- Sister position:

where
6 is the sister velocity (her position increases by 6 miles for every hour)
t is the time measured in hours
The sister catches up Jeff when the two positions are equal, so

And solving for t,

So, the sister catches Jeff after 2 hours.
Learn more about speed:
brainly.com/question/8893949
#LearnwithBrainly