Question

Aflați ultima cifră a nr 2^2018.
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Answer 1

Răspuns:

4

Explicație pas cu pas:

2=2^0=1

2^1=2}

2^2=4}. 2018÷4=504 r2

2^3=8}

2^4=16}. u(2^2018)=u(2^2)= 4

2^5=32

Answer 2

 

$\displaystyle\bf\\U\Big(2^{2018}\Big)=\\\\=U\Big(2^{2016+2}\Big)=\\\\=U\Big(2^{2016}\times2^2\Big)=\\\\=U\Big(2^{4\times504}\times2^2\Big)=\\\\=U\left(\Big(2^4\Big)^{504}}\times2^2\right)=\\\\=U\Big(16^{504}}\times2^2\Big)=\\\\=U\Big(6^{504}}\times2^2\Big)=\\\\=U\Big(6\times4\Big)=\\\\=U\Big(24\Big)=\boxed{\bf4}$