1: Evaluate the series \( $\dfrac{1}{3^1}+\dfrac{4}{3^2}+\dfrac{7}{3^3}+\dfrac{10}{3^4}+\cdots$.\)
∑ [ 3^-n(-2 + 3n), n, 1, ∞] ==It converges to 5/4 ==1.25
