Question

chung minh  2^0+2^1+2^2+2^3 chia het cho 3

Answer 1

\(2^0+2^1+2^2+2^3=\left(2^0+2^1\right)+\left(2^2+2^3\right)=\left(2^0+2\right)+2^2.\left(2^0+2\right)=3+2^2.3=3.\left(1+2^2\right)\)chia hết cho 3

Answer 2

2^0 + 2^1 + 2^2 + 2^3 = 1 + 2 + 4 + 8 = 15 

Vì 15 chia hết cho 3 => 2^0 + 2^1 + 2^ 2 + 2^3 chia hết cho 3