a)A=17^18+1/17^19+1 và B=17^17+1/17^18+1
=>17^18+1/17^19+1<1(vì tử bé hơn mẫu)
=>17^18+1/17^19+1<17^18+16+1/17^19+16+1=17^18+17/17^19+17=17(17^17+1)/17(17^18+1)=17^17+1/17^18+1=B Vậy A<B
b)B=2^2014-1/2^2015-1<1
=>2^2014-1/2^2015-1<2^2014-1-1/2^2015-1-1=2^2014-2/2^2015-2=2(2^2013-1)/2(2^2014-1)=2^2013-1/2^2014-1=A. Vậy A>B