题目是[﹙m²-4m+4﹚/m²-1] ÷ ﹙m-2/m-1 +2/m-1﹚?
还是m²-4m+﹙4/m²-1 ÷ m﹚-2/m-1 +2/m-1?
或者是[m²-4m+﹙4/m²-1﹚] ÷ ﹙m-2/m-1 +2/m-1﹚?