Problem 1
speed = distance/time
speed = (25.3 miles)/(4.6 hours)
speed = 5.5 mph
Then,
distance = speed*time
distance = (5.5 mph)*(3 hours)
distance = 16.5
Answer: 16.5 miles
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Problem 2
The linear function would be f(t) = 25t+10
The slope 25 tells us how much Kara saves from week to week. It's the rate of change. The 10 is her starting amount. It's the y intercept.
Replace f(t) with 335 and solve for t.
f(t) = 25t+10
335 = 25t+10
335-10 = 25t
325 = 25t
25t = 325
t = 325/25
t = 13
It will take 13 weeks for Kara to have $335 in her savings.
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Problem 3
This is a linear function because the height decreases the same amount for each hour. The slope is -1.75 to represent the decrease of 1.75 inches per hour. The y intercept is 12 because it's the starting height.
The function would be f(t) = -1.75t + 12
Replace f(t) with 6 to determine when it reaches half its starting height.
f(t) = -1.75t + 12
6 = -1.75t + 12
6-12 = -1.75t
-6 = -1.75t
-1.75t = -6
t = -6/(-1.75)
t = 3.42857 approximately
Round that value however needed.