Răspuns:
n = (2 · 5⁴)² ⇒ n este pătrat perfect
Explicație pas cu pas:
[tex][5^{3*7} : (1+4)^{10} - 5^{10}] : 5^2=\\\\(5^{21}:5^{10} - 5^{10}) : 5^2=\\\\(5^{21-10} - 5^{10}):5^2=\\\\(5^{11}-5^{10}) : 5^2=\\\\5^{10} (5-1) : 5 ^ 2= 4 * 5^{10}: 5^2 = 4 * 5^8 = (2* 5^4)^2[/tex]
