Question

(12^1980_2¹⁶⁰⁰⁾

^{chung minh chia hết cho 10}

Answer 1

Ta có :

\(12^{1980}=\left(12^4\right)^{470}=\left(\overline{....6}\right)^{470}=\left(\overline{....6}\right)\)

\(2^{1600}=\left(2^4\right)^{4000}=16^{4000}=\left(\overline{......6}\right)\)

\(\Rightarrow12^{1980}-2^{1600}=\left(\overline{....6}\right)-\left(\overline{....6}\right)=\left(\overline{....0}\right)\)

Vậy tổng có cs tận cùng là 0