3S=3+3²+3³+...+3¹⁰¹

3S-S=(3+3²+3³+...+3¹⁰¹)-(1+3+3²+3³+...+3¹⁰⁰)

2S=3+3²+3³+...+3¹⁰¹-1-3-...-3¹⁰⁰

2S=3¹⁰¹-1

\(S=\frac{3^{101}-1}{2}\)

Use the suggested words and phrases to write complete sentences of a passage. 1 she/decision/goodbye/him. 2 he/ surprise/ us/ go/ away/ without/ goodbye. 3 before/ give/ evidence/ you / must/ swear/ say/ truth. Thank you for your help^_^