Question

If the sum of the first $ n $ terms of an arithmetic progression is given by $ S_n = 3n^2 + 5n $, find the first term $ a $ and common difference $ d $.

• A. \( a=8, d=6 \)
• B. \( a=8, d=3 \)
• C. \( a=5, d=6 \)
• D. \( a=3, d=5 \)

Hint:

Tip: Remember, \( t_n = S_n - S_{n-1} \) is useful to find terms from sum expressions.