-3(3a^2-4)-(a^2-3a+5)+(4a-a^2),a=-3化简求值

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-3(3a^2-4)-(a^2-3a+5)+(4a-a^2),a=-3化简求值
-3(3a^2-4)-(a^2-3a+5)+(4a-a^2),a=-3
化简求值

-3(3a^2-4)-(a^2-3a+5)+(4a-a^2),a=-3化简求值
解-3(3a^2-4)-(a^2-3a+5)+(4a-a^2)
=-9a²+12-a²+3a-5+4a-a²
=-11a²+7a+7
=-11×(-3)²+7(-3)+7
=-99-21+7
=-113

-3(3a^2-4)-(a^2-3a+5)+(4a-a^2)
=﹣9a²+12-a²+3a-5+4a-a²
=﹣11a²+7a+7
当a=﹣3时,
原式=﹣11a²+7a+7
=﹣99-21+7
=﹣113.