Answer:
r=63
Step-by-step explanation:
Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
r/3-(21)=0 r
Simplify —
3
r
— - 21 = 0
3 2.1 Subtracting a whole from a fraction
Rewrite the whole as a fraction using 3 as the denominator :
21 21 • 3
21 = —— = ——————
1 3
Equivalent fraction : The fraction thus generated looks different but has the same value as the whole
Common denominator : The equivalent fraction and the other fraction involved in the calculation share the same denominator
Answer: If the initial term of an arithmetic sequence is a 1 and the common difference of successive members is d, then the nth term of the sequence is given by: a n = a 1 + (n - 1)d The sum of the first n terms S n of an arithmetic sequence is calculated by the following formula: S n = n (a 1 + a n)/2 = n [2a 1 + (n - 1)d]/2
Step-by-step explanation:

Answer:
The height of cone is decreasing at a rate of 0.085131 inch per second.
Step-by-step explanation:
We are given the following information in the question:
The radius of a cone is decreasing at a constant rate.

The volume is decreasing at a constant rate.

Instant radius = 99 inch
Instant Volume = 525 cubic inches
We have to find the rate of change of height with respect to time.
Volume of cone =

Instant volume =

Differentiating with respect to t,

Putting all the values, we get,

Thus, the height of cone is decreasing at a rate of 0.085131 inch per second.