Question

Sa se afle ultimele 2 cifre ale numerelor .A=1+2^2+2^4+2^6+2^8+.....2^2000​

Answer 1

A=1+2(2+4+6+...+2000)= 1+2(2×1+2×2+2×3+...+2×1000)= 1+4(1+2+3+4+...+1000)= 1+4(1000×1001÷2)=1+4×500500=1+2002000=2002001 => ult cifra este 1