Question

已知a=1999x+20000,b=1999x+2001,c=1999x+2002,则多项式a^2+b^2+c^2-ab

Answer 1

估计是a=1999x+2000

多项式= 0.5[(a^2- 2ab + b^2)+ (b^2 - 2bc + c^2)+ (c^2 - 2ca + a^2)]

= 0.5*[(a-b)^2 + (b-c)^2 + (c-a)^2]

=0.5*(1+1+4)

=3