cho A= -1,3 + 1/3^2 – 1/3^3 …….. + 1/3^50 – 1 /3^51 …. Tính a Question Thanh Hà cho A= -1,3 + 1/3^2 - 1/3^3 ........ + 1/3^50 - 1 /3^51 .... Tính a 5 years