Ta có :
\(B=ab56e+1cd8+a9c+7b5.\)
\(\Rightarrow ab\times1000+560+e+1000\times c\times100+d\times10+8\)
\(a\times100+90+c+700\times b+10+15\)
\(=\left(ab\times1000+c\times100+d\times10\right)+\left(a\times100+b\times10+c\right)+\left(560+1000+80+90+700\right)\)
\(=abcde+abc=2363\)
Có \(2001< 2363\)nên \(abcde+abc=2001< abcde+abc=2363\)
Vậy \(A< B\)