若3n²减n=1,求6n³+7n²减5n+2003的值

若3n²减n=1,求6n³+7n²减5n+2003的值
若3n²减n=1,求6n³+7n²减5n+2003的值

若3n²减n=1,求6n³+7n²减5n+2003的值
3n²-n=1
则
6n³+7n²-5n+2003
=6n³-2n²+9n²-3n-2n+2003
=2n(3n²-n)+3(3n²-n)-2n+2003
=2n+3-2n+2003
=2006

6n³+7n²-5n+2003
=9n²-3n+2003
=2006