I would choose A
You can simply try every answer and see which one gives you 16a-24ab
The answer would be $2.47
The series 7 + 16 + 25 +34 +43 +52 + 61 is an illusration of arithmetic series
The sigma notation of the series is: 
<h3>How to write the series in sigma notation?</h3>
The series is given as:
7 + 16 + 25 +34 +43 +52 + 61
The above series is an arithmetic series, with the following parameters
- First term, a = 7
- Common difference, d = 9
- Number of terms, n = 7
Start by calculating the nth term using:
a(n) = a + (n - 1) * d
This gives
a(n) = 7 + (n - 1) * 9
Evaluate the product
a(n) = 7 - 9 + 9n
Evaluate the difference
a(n) = 9n - 2
So, the sigma notation is:

Read more about arithmetic series at:
brainly.com/question/6561461
Answer:
Since the focus is at (-6,-11) and the directrix is at y=9:
The vertex is halfway between the focus and the directrix, so the vertex is at (-6,-1). (Draw this on graph paper if that doesn't make sense.)
The general form (conics form) of a parabola: 4p(y-k)=(x-h)^2 (vertex is (h,k) and "p" is the distance between the focus and vertex (or between vertex and directrix)).
(h,k) = (-6,-1)
p = 10 (distance between focus and vertex), so 4p = 40.
Therefore:
40(y+1)=(x+6)^2
Or if you need to rearrange to "vertex form": y=(1/40)(x+6)^2 - 1
Step-by-step explanation:
Given :
7x is an odd integer.
To Find :
The next odd integer as an algebraic expression in x.
Solution :
All positive integers are :
1 , 2 , 3 , 4 , 5 , ......
From the above series we noticed that every other odd number is 2 more than the previous one.
So , 7x is an odd number.
Therefore, next odd number is 7x + 2.
Hence, this is the required solution.