Question

bài 1:

a)A=4+4²+4³+........+4¹⁰⁰⁰

b) B=1-2+2²-2³+2⁴-2⁵+.........+2¹⁰⁰⁰

c) C=1-5+5²-5³+.....+5²⁰⁰