Answer:
The speed in still water is 5 miles per hour.
Step-by-step explanation:
distance with current = 90 miles
distance against current = 10 miles
speed in still water = s
speed of current = 4 mph
speed with current = s + 4
speed against current = s - 4
time = t
speed = distance/time
distance = speed * time
With current:
90 = (s + 4) * t
Against the current:
10 = (s - 4) * t
We have a system of equations:
90 = (s + 4) * t
10 = (s - 4) * t
90 = ts + 4t
10 = ts - 4t
Subtract the second equation from the first equation.
80 = 8t
10 = t
t = 10
10 = t(s - 4)
10 = 10(s - 4)
1 = s - 4
s = 5
Answer: The speed in still water is 5 miles per hour.
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<h3>>> Given Question :</h3>
3x²(4x³ - 2x² + 7x - 4)
<h3>>> Required Solution :</h3>
12x⁵ - 6x⁴ + 21x³ - 12x²
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Hello!
Here we are given a composite shape, meaning that we can divide this shape up into ways that we are given formulas to solve for legs and such.
I can see here that this can be divided into a triangle and a rectangle using a horizontal line.
The leg lengths of this triangle would be 9, because it is congruent to the bottom side of the rectangle, and 7, because it is the left side minus the right side.
This would also make a right triangle, meaning we could solve for the hypotenuse utilizing the Pythagorean Theorem.





Which is in simplest radical form.
Hope this helps!
The answer to the question is D