Answer:
Step-by-step explanation:
If the 2 is an exponent, it should be indicated with a circumflex: 4n^2+3n.
What is the first term?
a₁ = S₁ = 4·1² + 3·1 = 7
:::::
What is the common difference?
a₁ + a₂ = S₂ = 4·2² + 3·2 = 22
a₂ = 22-a₁ = 15
common difference d = a₂ - a₁ = 8
:::::
What is the arithmetic sequence?
The nth term is 7+(n-1)d = 7+(n-1)8 = 8n-1.
a₁ = 8·1-1 = 7
a₂ = 8·2-1 = 15
a₃ = 8·3-1 = 23
...