Good evening ,
Answer:
Is his formula correct and how do you know : <em>Yes</em>
Is it an explicit or recursive formula : <em>explicit </em>
Step-by-step explanation:
an = a1 + (n-1)r
a1 = 5
r = 8-5 = 3
Then an = 5 + 3(n-1).
:)
The length of the rectangle would be 21
Proportion to set it up would be 7/3 x X/9 cross multiply and solve for x which is 21
<span>C) 7 x 103 is twice as large as 5 x 102</span>
There are 20 gallons of 20% butterbeer solution.
Assume there are x gallons of 80% solution.
So total amount of the solution will be (x+20) gallons
The final solution is 50%.
So, we can set up the equation as:

.
Thus, there will be 20 gallons of 80% butterbeer solution that is needed to be mixed with 20 gallons of 20% butterbeer solution.
First, set up the formula.
V=pi*r^2*h
Substitute 10 for r and 15 for h.
V=pi*10^2*15
V=pi*100*15
V=pi*1500
V=4710 cubic feet
It takes 4710 cubic feet of water to fill the well.