Stim ca: [tex]S_{n}=b_{1}\times \frac{ q^{n}-1 }{q-1} [/tex]
b)
[tex] \\ b_{1}=2 \\ q=2 \\ n=20 \\ \\ S_{20} = 2\times \frac{ 2^{20}-1 }{2-1} \Rightarrow S_{20} = 2^{21}-2[/tex]
c)
[tex] \\ b_{1}=2 \\ q=2 \\ n=200 \\ \\ S_{200} = 2\times \frac{ 2^{200}-1 }{2-1} \Rightarrow S_{200} = 2^{201}-2[/tex]
