Answer:
f=1/x^2-81
Step-by-step explanation:
Step 1: Multiply both sides by x^2-81.
fx3−81fx=x
Step 2: Factor out variable f.
f(x3−81x)=x
Step 3: Divide both sides by x^3-81x.
f(x3−81x)
x3−81x
=x
x3−81x
f=
1
x2−81
Answer:
15 miles
Step-by-step explanation:
Let's say the dock is at the origin on a coordinate plane and each unit is 1 mile. If the boat travels 9 mile due north, that means that we move up from the origin (0, 0) 9 units to point A (0, 9). Now, this boat moves 12 miles due west, so we will go 12 units to the left of (0, 9) to point B (-12, 9). See the attached drawing (sorry for the crudeness).
Notice that this is a right triangle with legs of 9 and 12. That means the distance from the boat to the dock is just the hypotenuse, so use the Pythagorean Theorem: distance = 
Thus, the answer is 15 miles.
Hope this helps!
Answer: the rate of the jet in still air is 685 mph and the rate of the jetstream is 75 mph
Step-by-step explanation:
Let x represent the rate of the jet in still air.
Let y represent the rate of the jet jetstream.
Distance = speed × time
Flying against the jetstream, a jet travels 3050 miles in 5 hours. This means that the total speed of the jet would be (x - y) mph. Therefore,
3050 = 5(x - y)
3050/5 = x - y
x - y = 610 - - - - - - - - - - - - - -1
Flying with the jetstream, the same jet travels 3800 miles in 4 hours. This means that the total speed of the jet would be (x + y) mph. Therefore,
3800 = 4(x + y)
3800/5 = x + y
x + y = 760 - - - - - - - - - - - - - -2
Adding equation 1 to equation 2, it becomes
2x = 1370
x = 1370/2 = 685mph
Substituting x = 685 into equation 1, it becomes
685 - y = 610
y = 685 - 610 = 75mph
Let us assume base of the window = b feet.
Height is 3 feet less than base, that is = (b-3).
Given area of the triangle = 20 feet square.
We know formula for area of a triangle:
Area =
× Base × Height
Plugging values in formula, we get
20 = 




Factoring quadratic, we get
=0
b+5=0
b=-5
b-8=0
b=8.
For base we can take only positive value.
<h3>Therefore, base of the triangle = 8 feet and height = 8 -3 = 5 feet.</h3>
Equations don't have minimum or maximum, functions do.
Function y=2n^2+5n-25 has minimum -28.125, has no maximum.