The summation of the first five terms having first term 2.2 and common difference 6.6 is 77.
A series is a sum of sequence terms. That is, it is a list of numbers with adding operations between them.
The series is 2.2 + 8.8 + 15.4 + ....
The first term (a) = 2.2
And the common difference (d) = 8.8 - 2.2 = 15.4 - 8.8 = 6.6
The sum of n terms is given by
[tex]\rm S_n = \dfrac{n}{2 }[2a+(n-1)d][/tex]
For the first 5 terms, we have
[tex]\rm S_5 = \dfrac{5}{2 }[2*2.2+(5-1)6.6]\\\\S_5 = \dfrac{5}{2 }[2*2.2+4*6.6]\\\\S_5 = (2.5)(4.4 +26.4)\\\\S_5 = 77[/tex]
More about the series link is given below.
https://brainly.com/question/10813422
