Question

Encontre a soma dos vinte termos da PG ( 2,6,18....)

Answer 1

$sn= \frac{a1.( q^{n}-1) }{q-1} = s20 \frac{2.( 3^{20} -1)}{3-1} = s20= \frac{2.(3486784401-1)}{2} = s20= \frac{2.348678440}{2} = s20= \frac{6973568800}{2} = s20=348678440$