4－4x＋x的2次方分支2x－6除以x加3括号乘以3－x分之x的平方＋x－6=2(x-3)/(2-x)² ÷ (x+3) × (x-2)(x+3)/(3-x)=-2/(x-2)=-2/(-1/2 -2)=4/5
