SOLUTION: The function Upper D(t) = 17t^2 - 100t gives the distance a car going a certain speed will skid in t seconds. Find the time it would take for the car to skid 190 feet.

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Question 1115545: The function Upper D(t) = 17t^2 - 100t gives the distance a car going a certain speed will skid in t seconds. Find the time it would take for the car to skid 190 feet.
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

D%28t%29+=+17t%5E2+-+100t gives the distance a car going a certain speed will skid in t+seconds.
Find the time it would take for the car to skid D%28t%29+=190 feet.
D%28t%29+=+17t%5E2+-+100t...substitute D%28t%29
190+=+17t%5E2+-+100t
17t%5E2+-+100t-190=0...use quadratic formula

t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
t+=+%28-%28-100%29+%2B-+sqrt%28+%28-100%29%5E2-4%2A17%2A%28-190%29+%29%29%2F%282%2A17%29+
t+=+%28100+%2B-+sqrt%28+10000%2B12920+%29%29%2F34+
t+=+%28100+%2B-+sqrt%28+22920+%29%29%2F34+
t+=+%28100+%2B-+151.39%29%2F34+...use positive value
t+=+%28100+%2B+151.39%29%2F34+
t+=+251.39%2F34+
t+=7.39+ seconds