已知A=4x²-10x+8,B=5x²-6x+8,C=2x²-3,①求(a-b)*C②当X=-2时,求(A-b)*C
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![已知A=4x²-10x+8,B=5x²-6x+8,C=2x²-3,①求(a-b)*C②当X=-2时,求(A-b)*C](/uploads/image/z/766113-33-3.jpg?t=%E5%B7%B2%E7%9F%A5A%3D4x%26%23178%3B-10x%2B8%2CB%3D5x%26%23178%3B-6x%2B8%2CC%3D2x%26%23178%3B-3%2C%E2%91%A0%E6%B1%82%28a-b%29%2AC%E2%91%A1%E5%BD%93X%3D-2%E6%97%B6%2C%E6%B1%82%EF%BC%88A-b%29%2AC)
已知A=4x²-10x+8,B=5x²-6x+8,C=2x²-3,①求(a-b)*C②当X=-2时,求(A-b)*C
已知A=4x²-10x+8,B=5x²-6x+8,C=2x²-3,①求(a-b)*C②当X=-2时,求(A-b)*C
已知A=4x²-10x+8,B=5x²-6x+8,C=2x²-3,①求(a-b)*C②当X=-2时,求(A-b)*C
1、
(A-B)C
=(4x²-10x+8-5x²+6x-8)(2x²-3)
=(-x²-4x)(2x²-3)
=-2x⁴--8x³+3x²+12x
2、
x=-2
原式=-32+64+12-24=20