Ok here’s the answer! I again had to crop out the first step. here it was to divide equation 1 by 3 and add that to equation 2. all you need do you show that step is to write equation 1: -3x+2y=8 and equation 2: (11y/3)=35/3
Answer: First Option : Sₙ= n/2(a₁ + aₙ)
Step-by-step explanation:
The nth partial sum of an arithmetic sequence or the sum of the first n terms of the arithmetic series can be defined as the sum of a finite number of term in an arithmetic sequence.
It is calculated using the formula:
Sₙ= n/2(a₁ + aₙ)
Where :
a₁ = First term
aₙ = last term
n = number of terms