Question

chung minh a chia het cho 3

2⁰ + 2¹ + 2² + 2³ +...+ 2²⁰⁰⁹ + 2²⁰¹⁰

Answer 1

2^0+2^1+2^2+2^3+...+2^2009+2^2010

=(2^0+2^1)+(2^2+2^3)+...+(2^2009+2^2010)

=(1+2)+2^2(1+2)+...+2^2009(1+2)

=3(1+2^2+...+2^2009) chia hết cho 3

tick nha bạn