Câu a,
Có A=2015.2017=(2016-1)(2016+1)=2016^{2}-1< 2016^{2}=B
Vậy A<B
Câu b,
Có C=(2-1)(2+1)(2^{2}+1)(2^{4}+1)(2^{8}+1)(2^{16}+1)
\Leftrightarrow C=(2^{2}-1)(2^{2}+1)(2^{4}+1)(2^{8}+2)(2^{16}+1)
\Leftrightarrow C=(2^{4}-1)(2^{4}+1)(2^{8}+1)(2^{16}+1)
\Leftrightarrow...