Răspuns :
d=4^48*(4^2+4+1):21=4^48 * 21 : 21 = 4^48 = 4^24 * 4^24 --> patrat perfect
d=4^48 = (2^2)^48=2^96=2^(3*32)=(2^32)^3 ---> cub perfect
d=4^48 = (2^2)^48=2^96=2^(3*32)=(2^32)^3 ---> cub perfect
4⁴⁸(4²+4+1):21=
4⁴⁸21:21=
=4⁴⁸
4⁴⁸=4²⁾²⁴=4²⁴x4²⁴ patrat perfect
4⁴⁸=4³⁾¹⁶=4¹⁶x4¹⁶x4¹⁶ cub perfect