Answer:
4
Step-by-step explanation:
A(n)=4+4(n-1)
a(n)=4+4n-4
a(n)=4n
76=4n
n=19
The sum of any arithmetic sequence (series are infinite) is:
(a+a(n))(n/2)
The average of the first and last terms times the number of terms, in this case we found that n=19 so:
19(4+76)/2=760
Answers:
- Original = 1 ----> Enlarged = 6
- Original = 7 ----> Enlarged = 42
- Original = 2.5 ----> Enlarged = 15
- Original = 6 ----> Enlarged = 30
It looks like you have the correct order. To get those answers above, we simply multiply the original length by the scale factor 6.
Example: 7*6 = 42
