Question

calcula a soma dos vinte primeiros termos da pg, cujo primeiro termo é 1 e a razao e 2

Answer 1

$\mathrm{a_1=1\ \ \| \ \ q=2\ \ \|\ \ n=20}\\\\\\ \mathrm{S_n=a_1\bigg(\dfrac{q^n-1}{q-1}\bigg)\ \to\ S_{20}=1\bigg(\dfrac{2^{20}-1}{2-1}\bigg)=}\\\\\\ \mathrm{=\dfrac{2^{20}-1}{1}\ \to\ \boxed{\mathbf{S_{20}=2^{20}-1}}\ \ ou\ \ \boxed{\mathbf{S_{20}=1.048.575}}}$