Question

A={×|×€N,5la puterea x , B={×|×€N,(7la puterea 0+1la puterea 1999+1la puterea2000+1 la puterea 2001)totul la puterea x <64}

Answer 1

A=5^0,5^1,5^2,5^3,5^4,5^5,5^6,5^7,5^8,5^9
A=1,5,25,125,625,3125,15625,78125,390625,1953125.
B=
7^0=1
1^1999=1
1^2000=1
1^2001=1
1+1+1+1=4
4^0=1
4^1=4
4^2=16