A = 1 + 2012 + 20122 + ... + 2012100
2012A = 2012 + 20122 + 20123 + ... + 2012101
2012A - A = (2012 + 20122 + 20123 + ... + 2012101) - (1+ 2012 + 20122 + ...+ 2012100)
2011A = 2012101 - 1
A = \(\frac{2012^{101}-1}{2011}\)
=> B - A = \(\frac{2012^{101}}{2011}-\frac{2012^{101}-1}{2011}=\frac{2012^{101}-\left(2012^{101}-1\right)}{2011}=\frac{2012^{101}-2012^{101}+1}{2011}=\frac{1}{2011}\)