Inactive Tutor answered 01/29/13
Try the rule for adding exponents when multiplying terms:
x=(1000000000000000000001)^20
x^2+x =[(1000000000000000000001)^20]*[(1000000000000000000001)^20] +
(1000000000000000000001)^20
= {(1000000000000000000001)^40} + (1000000000000000000001)^20
Don't let all the zeros baffle you.
BruceS