Найдите сумму первых 6 членов геометрической прогрессии 32/27, 16/9

Question

Найдите сумму первых 6 членов геометрической прогрессии 32/27, 16/9

Answer 1

32/27;16/9....   b1=32/27
b2/b1=q=16/9*27/32=  3/2

s6=(32/27)(q⁶-1)/(q-1)
s6= (32/27)(729/64-1)/(3/2-1)=2*32/27*665/64=665/27=24 17/27

Answer 2

Q=b2/b1=16/9•27/32=(16•27)/(9•32)=
=3/2
S6=b1•(q^5–1)/(q–1)=
=32/27•(243/32–1)/(1/2)=
=(32/27•211/32)/(1/2)=
=(32•211•2)/(27•32)=422/27=15 17/27