Câu hỏi 9Tính $1+1/3+1/3^2+\cdots+1/3^{10}$.$\frac32-\frac1{2\cdot3^{11}}$$\frac32-\frac1{2\cdot3^{10}}$$\frac1{2\cdot3^{10}}$$\frac1{3^{10}}$$\frac1{3^{11}}$