Răspuns :
[tex]2^{44}\times25^2\times7^4=\\ =2^{44}\times(5^2)^2\times7^4=\\ =2^{44}\times5^4\times7^4=\\ =2^{40+4}\times5^4\times7^4=\\ =2^{40}\times 2^4\times5^4\times7^4 =\\ =2^{40}\times(2^4\times5^4)\times7^4=\\ =2^{40}\times(2\times5)^4\times7^4=\\ =2^{40}\times10^4\times7^4=\\ =2^{40}\times7^4\times10^4=\\ =2^{4\times10}\times7^4\times10^4=\\ =(2^4)^{10}\times7^4\times10^4=\\ =16^{10}\times7^4\times10^4=\\ =16^{10}\times7^4\times10000\\\\ U(16^{10})=6 \\ U(7^4)=1 [/tex]
Unde U() inseamna ultima cifra.
⇒ Ultimele 5 cifre ale numarului sunt:
6 × 1 × 10000 = 60000
Rezulta ca numarul se termina in 4 zerouri
2^44x25^2x7^4=2^4x5^4x2^40x7^4=10^4xA, unde A este un nr care nu se termina in 0. Deci numarul rezultat din calcule se va termina in 4 zerouri(de la 10^4=10000)
Succes!
Succes!