Downstream DATA:
distance = 12 miles
time = 2 hours
rate = 12/2 = 6 mph
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Upstream DATA:
distance = 12 miles
time = 4 hrs
rate = 12/4 = 3 mph
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Equations:
Downstream: b + c = 6
Upstream::: b - c = 3
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Add to get:
2b = 9
b = 4.5 mph (speed of the boat in still water.)
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Solve for "c":
b + c = 6
4.5 + c = 6
c = 1.5 mph (speed of the current)
The answer is 1.5 mph
Step-by-step explanation:
I assume that "ground" is at 0 ft height. which is in an actual scenario not airways the case.
y = -16x² + 64x + 89
shows us that the tower is 89 ft tall (the result for x = 0, at the start).
anyway, if the original assumption is correct, then we need to solve
0 = -16x² + 64x + 89
the general solution for such a quadratic equation is
x = (-b ± sqrt(b² - 4ac))/)2a)
in our case
a = -16
b = 64
c = 89
x = (-64 ± sqrt(64² - 4×-16×89))/(2×-16) =
= (-64 ± sqrt(4096 + 5696))/-32 =
= (-64 ± sqrt(9792))/-32
x1 = (-64 + 98.95453501...)/-32 = -1.092329219... s
x2 = (-64 - 98.95453501...)/-32 = 5.092329219... s
the negative solution for time is but useful here (it would be the time calculated back to ground at the start).
so, x2 is our solution.
the rocket hits the ground after about 5.09 seconds.
Length = 20 ft
If he uses 60 ft of fencing to line his rectangular backyard, then the perimeter is 60 ft.
Perimeter formula is ((Width × 2) + (Length × 2))
10 × 2 = 20
20 × 2 = 40
40 + 20 = 60
1199.3 (I'm assuming you mean round to the nearest tenth)