Question

设m^(2)+m-1=0.求m^(3)+2m^(2)+2004的值

Answer 1

m^(3)+2m^(2)

=m^(3)+m^(2)+m^(2)------------拆开2m^(2)

=m(m^(2)+m)+m^2--------------前两顶提出m

=m+m^2-----------------------括号内是1

=m^(2)+m----------------------加法交换律