（x+2/x²-2x - x-1/x²-4x+4）÷ x-4/x={(x+2)(x-2)/[x(x-2)²]-x(x-1)/[x(x-2)²] } ·x/(x-4)={(x²-4-x²＋x)/[x(x-2)²] } ·x/(x-4)=(x-4)/[x(x-2)²] ·x/(x-4)=1/(x-2)²=1/(3/2-2)²=1/(-1/2)²=4
