For the infinite geometric series with $a = 81$, $r = -\dfrac{1}{3}$, the sum to infinity is —

Question

Accepted Answer

$\dfrac{243}{4}$

Answer

$\dfrac{81}{4}$

Answer

$\dfrac{81}{2}$

Answer

$-\dfrac{81}{2}$

For the infinite geometric series with a=81a = 81a=81, r=−13r = -\dfrac{1}{3}r=−31​, the sum to infinity is —