100%-15%=85% -- 0.85
A. doesn't work because it is increasing
B. works because your finding 85 percent since you decrease by 15 percent
C. doesn't work because you are not taking 15 percent from value of t
D. doesn't work because finging 15 percent of t and them subtracting from one won't give you the right answer
E.doesnt work because all you have to do is find 85 percent not subtract that from the original value
F.works because subtracting 15 percent from one and multiply by t would give the equation from B
So the answers are B and F
Convert from degrees to radians using the ratio
π/180. 3aπ/2 radians
is this what you need?
or 90 degress
Answer:
This is the rate at which the radius of the balloon is changing when the volume is 300 
Step-by-step explanation:
Let 
be the radius and 
the volume.
We know that the gas is escaping from a spherical balloon at the rate of 
because the volume is decreasing, and we want to find 
The two variables are related by the equation
taking the derivative of the equation, we get
With the help of the formula for the volume of a sphere and the information given, we find
![V=\frac{4}{3}\pi r^3\\\\300=\frac{4}{3}\pi r^3\\\\r^3=\frac{225}{\pi }\\\\r=\sqrt[3]{\frac{225}{\pi }}](https://tex.z-dn.net/?f=V%3D%5Cfrac%7B4%7D%7B3%7D%5Cpi%20r%5E3%5C%5C%5C%5C300%3D%5Cfrac%7B4%7D%7B3%7D%5Cpi%20r%5E3%5C%5C%5C%5Cr%5E3%3D%5Cfrac%7B225%7D%7B%5Cpi%20%7D%5C%5C%5C%5Cr%3D%5Csqrt%5B3%5D%7B%5Cfrac%7B225%7D%7B%5Cpi%20%7D%7D)
Substitute the values we know and solve for
![\frac{dV}{dt}=4\pi r^2 \frac{dr}{dt}\\\\\frac{dr}{dt}=\frac{\frac{dV}{dt}}{4\pi r^2} \\\\\frac{dr}{dt}=-\frac{12}{4\pi (\sqrt[3]{\frac{225}{\pi }})^2} \\\\\frac{dr}{dt}=-\frac{3}{\pi \left(\sqrt[3]{\frac{225}{\pi }}\right)^2}\\\\\frac{dr}{dt}=-\frac{3}{\pi \frac{225^{\frac{2}{3}}}{\pi ^{\frac{2}{3}}}}\\\\\frac{dr}{dt}=-\frac{3}{225^{\frac{2}{3}}\pi ^{\frac{1}{3}}} \approx -0.05537 \:\frac{ft}{h}](https://tex.z-dn.net/?f=%5Cfrac%7BdV%7D%7Bdt%7D%3D4%5Cpi%20r%5E2%20%5Cfrac%7Bdr%7D%7Bdt%7D%5C%5C%5C%5C%5Cfrac%7Bdr%7D%7Bdt%7D%3D%5Cfrac%7B%5Cfrac%7BdV%7D%7Bdt%7D%7D%7B4%5Cpi%20r%5E2%7D%20%5C%5C%5C%5C%5Cfrac%7Bdr%7D%7Bdt%7D%3D-%5Cfrac%7B12%7D%7B4%5Cpi%20%28%5Csqrt%5B3%5D%7B%5Cfrac%7B225%7D%7B%5Cpi%20%7D%7D%29%5E2%7D%20%5C%5C%5C%5C%5Cfrac%7Bdr%7D%7Bdt%7D%3D-%5Cfrac%7B3%7D%7B%5Cpi%20%5Cleft%28%5Csqrt%5B3%5D%7B%5Cfrac%7B225%7D%7B%5Cpi%20%7D%7D%5Cright%29%5E2%7D%5C%5C%5C%5C%5Cfrac%7Bdr%7D%7Bdt%7D%3D-%5Cfrac%7B3%7D%7B%5Cpi%20%5Cfrac%7B225%5E%7B%5Cfrac%7B2%7D%7B3%7D%7D%7D%7B%5Cpi%20%5E%7B%5Cfrac%7B2%7D%7B3%7D%7D%7D%7D%5C%5C%5C%5C%5Cfrac%7Bdr%7D%7Bdt%7D%3D-%5Cfrac%7B3%7D%7B225%5E%7B%5Cfrac%7B2%7D%7B3%7D%7D%5Cpi%20%5E%7B%5Cfrac%7B1%7D%7B3%7D%7D%7D%20%5Capprox%20-0.05537%20%5C%3A%5Cfrac%7Bft%7D%7Bh%7D)
<u>136 + x + x = 180. Or, to simplify, 136 + 2x = 180. The congruent angles measure 23 degrees each.</u>
We know this because of a simple rule that goes for all triangles: The measures of all three angles in a triangle will <em>always</em> add up to 180 degrees.
One angle of a triangle measures 136 degrees. The other two angles are congruent (have the same measure).
(x stands for an unknown angle measure.) So the equation we would use is 136 + 2x = 180. We can solve this within a few steps.
1. We subtract 136 from 2x in order to isolate 2x. But if we subtract something from the left side of the equation, we have to subtract it from the right side too. Otherwise the equation will be wrong; We would be taking away the balance.
2x = 180 - 136
2. Now that 2x is isolated, we solve 180 - 136.
2x = 46
3. If we know now that 2x is equal to 46, how do we find out what x is equal to? We divide by 2 (on both sides or it'll be wrong) to get x.
2x = 46
2x/2 = 46/2
x = 23
Now we know! x = 23... The other two angles are both 23 degrees. We can check to see if that's right by solving 23 + 23 + 136... Does it add up to 180? Yes! :)
