Question

x的平方加x减2等于0,求x的3次方加3x的平方加2004

Answer 1

由x2+x-2=0,得x2+x=2

x3+3x2+2004

=x3+x2+2x2+2004

=x(x2+x)+2x2+2004

=2x+2x2+2004

=4+2004

=2008