求(2x²-18)÷(4-4x+x²)÷(x+3)·(x-2)÷(3-x)的值
问题描述:
求(2x²-18)÷(4-4x+x²)÷(x+3)·(x-2)÷(3-x)的值
答
(2x²-18)÷(4-4x+x²)÷(x+3)·(x-2)÷(3-x)
=2(x²-9)÷[(x+2)(x-2)]÷(x+3)*(x-2)÷(3-x)
=2[ (x-3) (x+3)]÷[(x+2)(x-2)]÷(x+3)*(x-2)÷(3-x)
=2(x-3)÷[(x+2)(x-2)]*(x-2)÷(3-x)
=-2÷[(x+2)(x-2)]*(x-2)
=-2÷(x+2)