题目内容
26、已知t2+t-1=0,则t3+2t2+2008=
2009
.分析:首先由t2+t-1=0求得t2+t的值,然后将t3+2t2+2008变形为t(t2+t)-t2+2t2+2008,即可求得答案.
解答:解:∵t2+t-1=0,
∴t2+t=1,
∴t3+2t2+2008=t(t2+t)-t2+2t2+2008,
=t+t2+2008,
=1+2008,
=2009.
故答案为:2009.
∴t2+t=1,
∴t3+2t2+2008=t(t2+t)-t2+2t2+2008,
=t+t2+2008,
=1+2008,
=2009.
故答案为:2009.
点评:此题考查了因式分解的应用,解题的关键是t3+2t2+2008=t(t2+t)-t2+2t2+2008式子的求得与整体思想的应用.
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