(1)-3a-(-2a+2b-c)(2)4a²+3b²+2ab-4ab-4b² (3)3x-4x²+7-3x+2x²+1求值:(-8x²+6x)-(5x²-4x+1)其中x=-1
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![(1)-3a-(-2a+2b-c)(2)4a²+3b²+2ab-4ab-4b² (3)3x-4x²+7-3x+2x²+1求值:(-8x²+6x)-(5x²-4x+1)其中x=-1](/uploads/image/z/469485-45-5.jpg?t=%EF%BC%881%EF%BC%89-3a-%EF%BC%88-2a%2B2b-c%EF%BC%89%EF%BC%882%EF%BC%894a%26%23178%3B%2B3b%26%23178%3B%2B2ab-4ab-4b%26%23178%3B+%EF%BC%883%EF%BC%893x-4x%26%23178%3B%2B7-3x%2B2x%26%23178%3B%2B1%E6%B1%82%E5%80%BC%EF%BC%9A%EF%BC%88-8x%26%23178%3B%2B6x%EF%BC%89-%EF%BC%885x%26%23178%3B-4x%2B1%EF%BC%89%E5%85%B6%E4%B8%ADx%3D-1)
(1)-3a-(-2a+2b-c)(2)4a²+3b²+2ab-4ab-4b² (3)3x-4x²+7-3x+2x²+1求值:(-8x²+6x)-(5x²-4x+1)其中x=-1
(1)-3a-(-2a+2b-c)(2)4a²+3b²+2ab-4ab-4b² (3)3x-4x²+7-3x+2x²+1
求值:(-8x²+6x)-(5x²-4x+1)其中x=-1
(1)-3a-(-2a+2b-c)(2)4a²+3b²+2ab-4ab-4b² (3)3x-4x²+7-3x+2x²+1求值:(-8x²+6x)-(5x²-4x+1)其中x=-1
(1)-3a-(-2a+2b-c)
=-3a+2a-2b+c
=-a-2b+c
(2)4a²+3b²+2ab-4ab-4b²
=4a²-2ab-b²
(3)3x-4x²+7-3x+2x²+1
=-2x²+8
(-8x²+6x)-(5x²-4x+1)
=-13x²+10x-1
=-13×(-1)²-4×(-1)-1
=-13+4-1
=-10
(1)-3a-(-2a+2b-c)
=-3a+2a-2b+c
=-a-2b+c
(2)4a²+3b²+2ab-4ab-4b²
=4a²-2ab-b²
(3)3x-4x²+7-3x+2x²+1
=-2x²+8
求值:(-8x²+6x)-(5x²...
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(1)-3a-(-2a+2b-c)
=-3a+2a-2b+c
=-a-2b+c
(2)4a²+3b²+2ab-4ab-4b²
=4a²-2ab-b²
(3)3x-4x²+7-3x+2x²+1
=-2x²+8
求值:(-8x²+6x)-(5x²-4x+1)其中x=-1
=-8x²+6x-5x²+4x-1
=-13x²+10x-1
=-13*(-1)²+10*(-1)-1
=-13-10-1
=-24
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