∵t²+t-1=0
∴t²=1-t
t³+2t+2008
原式=t²(t+2)+2008
=(1-t)(t+2)+2008
=t+2-t²-2t+2008
=t+2-(1-t)-2t+2008
=t-1+t-2t+2010
=2010-1
=2009
∵t²+t-1=0
∴t²=1-t
t³+2t+2008
原式=t²(t+2)+2008
=(1-t)(t+2)+2008
=t+2-t²-2t+2008
=t+2-(1-t)-2t+2008
=t-1+t-2t+2010
=2010-1
=2009