Answer:

Step-by-step explanation:
Given:
Rate of change of radius of cylinder:

(This is increasing rate so positive)
Rate of change of height of cylinder:

(This is decreasing rate so negative)
To find:
Rate of change of volume when r = 20 inches and h = 16 inches.
Solution:
First of all, let us have a look at the formula for Volume:

Differentiating it w.r.to 't':

Let us have a look at the formula:


Applying the two formula for the above differentiation:

Now, putting the values:

So, the answer is: 
Y^4-4y^3+7y^2-6y-2y^3+8y^2-14y+12=
y^4-6y^3+15y^2-20y+12
or
y^3-4y^2+7y-6=y^3-4y^2+4y+3y-6=
y(y^2-4y+4)+3(y-2)=
y(y-2)^2+3(y-2)=(y-2)[y(y-2)+3]=(y-2)(y^2-2y+3)
(y^3-4y^2+7y-6)(y-2)=(y-2)^2(y^2-2y+3)
The solution is
and 
Step-by-step explanation:
The expression is
and 
Using substitution method we can solve the expression.
Let us substitute
in 

Expanding and simplifying the expression, we get,

Let us use the quadratic equation formula to solve this equation,

Thus,
and 
Substituting y-values in the equation
, we get the value of x.
For
⇒ 
For
⇒ 
Thus, the solution set is
and 
I think 320 is the answer ✋