Question

chứng minh ; b) 2^ 23 +2^24-2^20chia hết cho 23

 

Answer 1

trả lời hộ minh

 

Answer 2

2²³+2²⁴-2²⁰=2²⁰.(2³+2⁴-1)=2²⁰.23

⇒2²³+2²⁴-2²⁰⋮23

Answer 3

\(2^{23}+2^{24}-2^{20}\)

\(=2^{20}\left(2^3+2^4-1\right)\)

\(=2^{20}\left(8+16-1\right)\)

\(=2^{20}.23\)

Mà \(23⋮23\)nên \(\left(2^{20}.23\right)⋮23\)

Vậy \(\left(2^{23}+2^{24}-2^{20}\right)⋮23\)