(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)