Answer:
d = 13.8 feet
Step-by-step explanation:
Because we are talking about cubic feet of water, we need the formula for the VOLUME of a cylinder. That formula is
![V=\pi r^2h](https://tex.z-dn.net/?f=V%3D%5Cpi%20r%5E2h)
We will use 3.141592654 for pi; if the tank HALF filled with water is at 20 feet, then the height of the tank is 40 feet, so h = 40; and the volume it can hold in total is 6000 cubic feet. Filling in then gives us:
![6000=(3.141592654)(r^2)(40)](https://tex.z-dn.net/?f=6000%3D%283.141592654%29%28r%5E2%29%2840%29)
Simplify on the right to get
![6000=125.6637061r^2](https://tex.z-dn.net/?f=6000%3D125.6637061r%5E2)
Divide both sides by 125.6637061 to get that
![r^2=47.74648294](https://tex.z-dn.net/?f=r%5E2%3D47.74648294)
Taking the square root of both sides gives you
r = 6.90988299
But the diameter is twice the radius, so multiply that r value by 2 to get that the diameter to the nearest tenth of a foot is 13.8
Answer:
a = 6/5
b = 7/8
c = 1/5
Step-by-step explanation:
We want to make two of these equations be in terms of the same variable, so let's solve the first and third in terms of b.
5a-24b=-15 -> -3 + 24b/5 = a
48b+35c = 49 -> 49/35 - 48b/35 = 7/5 - 48b/35 = c
Now we can replace the a and c in the second equation and solve for b.
10a+45c=21
10(-3+24b/5)+45(7/5 - 48b/35) = 21
-30 + 48b + 63 - 432b/7 = 21 -> -12 = -96b/7 -> b=7/8
Now we can plug b back into the other two to solve for a and c. I will leave that to you unless you would like the steps there.
Answer: 88 years
Step-by-step explanation:
Let x represent the length of the side of the pen that is parallel to the barn. Then the area (y) will be
.. y = x(300 -x)/2
This describes a downward opening parabola with zeros at x=0 and x=300. The vertex (maximum) will be found at the value of x that is halfway between those, x = 150.
For that value of x, the pen area is
.. y = 150(300 -150)/2 = 150^2/2 = 11,250 . . . . . square feet.
I can’t really see the graph