Câu hỏi của Nguyễn Minh

Question

Tìm chữ số tận cùng của các số sau:51⁵¹,99⁹⁹,22²²,222¹⁰¹ giúp mình nhé

Victorique de Blois · Accepted Answer

$51^{51}=\overline{.....1}$

$99^{99}=\left(99^2\right)^{49}\cdot9=\overline{....1}^{49}\cdot9=\overline{....1}\cdot9=\overline{....9}$

$22^{22}=\left(22^4\right)^5\cdot2^2=\overline{...6}^5\cdot4=\overline{...6}\cdot4=\overline{....4}$

$222^{101}=\left(222^4\right)^2^5\cdot222=\overline{...6}^{25}\cdot222=\overline{....6}\cdot222=\overline{....2}$

Câu trả lời:

$51^{51}=\overline{.....1}$

$99^{99}=\left(99^2\right)^{49}\cdot9=\overline{....1}^{49}\cdot9=\overline{....1}\cdot9=\overline{....9}$

$22^{22}=\left(22^4\right)^5\cdot2^2=\overline{...6}^5\cdot4=\overline{...6}\cdot4=\overline{....4}$

$222^{101}=\left(222^4\right)^2^5\cdot222=\overline{...6}^{25}\cdot222=\overline{....6}\cdot222=\overline{....2}$