解
[6(x-2)²+12(x+2)(x-2)-3(x-1)²(x-2)]÷[3(2-x)]
=3(x-2)[2(x-2)+4(x+2)-(x-1)²]÷[-3(x-2)]
=-[2(x-2)+4(x+2)-(x-1)²]
=-(2x-4+4x+8-x²+2x-1)
=-(8x-x²+3)
=x²-8x-3