Answer:
C, 6
Step-by-step explanation:
31-13 is 18, 18/3 is 6.
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.
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Answer:
π (or 270°)
Step-by-step explanation:
I use the trick with the coordinates.
(0, -1)
cos270° = 0 (the x-coordinate)
sin270° = -1 (the y-coordinate)
This trick works depending on the radius.
Answer:
its C
Step-by-step explanation:
f(x) = |(-5)+1|
f(x)=|4|
absolute value of 4 is 4