Answer:
Her friend got the better deal.
Step-by-step explanation:
For Jillians equation look at
$22.56/4 = $6.39 per CD
For her friends equation look at
$18.45/3 = $6.15 per CD
Jillian's friend got the better deal because she paid less per CD as shown in the equations above.
Answer:
C
Step-by-step explanation:
1 1/4 = 1.25
1 4/5 = 1.8
1.8+1.25=3.05=3 1/20
Answer:
5
Step-by-step explanation:
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