Answer:
Step-by-step explanation:
I answered another one of your questions so I will not explain as much. ther are 12 inches in a foot and then 5280 feet in a mile so that's 1 ft/ 12 in and 1 mi/ 5280 ft. So the math is 20 in * 1 ft/ 12 in * 1 mi/ 5280 ft = .000315 mi.
In reference to the last one, do keep in mind "square" inches and whatnot mean you square things. so 1 ft/ 12 in becomes 1 ft^2/ 144 in^2. Just as a small heads up to what could be tricky.
So Volume of cylinder is pi*r^2*h = 1,000
Then lightest one means you have the smallest surface area. Which is one base and then the area of the surface. SA = pi*r^2 + 2pi*r*h
So now you have 2 equations, so:
h = 1,000/(pi*r^2)
So then SA = pi*r^2 + 2pi*r*(1,000/(pi*r^2) = pi*r^2 + 2,000/r
Derivative of SA is then 2pi*r -2,000/r^2. Set to 0
2pi*r-2,000/r^2 =0 --> 2pi*r^3 = 2,000 --> r^3 = 1,000/pi --> r = 10/pi^(1/3)
Now go back to the volume function: pi*r^2*h =1,000 --> 1,000/(pi*100/pi^(2/3)) = h
<span>h = 10 / pi^(1/3)</span>
Answer:
(3,13)
Step-by-step explanation:
Because the smallest x value is 3 and 3 is the closest to 0.
In 7th grade:
red-hair students =58
another color hair students =609
In 8th grade:
red-hair students =60
Let's assume
another color hair students =x
now, we are given
The numbers of red-haired students in 8th grade are proportional to the numbers in 7th
so,
now, we can solve for x
we get
we get
so, students have another color hair in 8th grade is 630.........Answer
okay so we need to solve for x.
--
FIRST STEP: 12x^2+5x-4=12^2x+6 would turn into x2 + 5x - 4 = 2x + 6 so it'd have equal bases.
SECOND STEP: move any number with "x" in it to the left side. it ends up as x2 + 3x - 4 = 6
THEN, we use the AC method to eliminate any unnecessary numbers.
you should end up with ( x - 2) (x + 5) = 0
SO, the answer is your third option. ( x = 2, x = -5)
