把分子提取2,则可约分为盯派罩2 (6/11+2/7+8/9)/(1/7+3/11+4/9)=2×(1/7+3/11+4/9﹚)/(1/7+3/凯闹羡念11+4/9)=2
(6/11+2/键州7+8/9)/稿嫌(1/7+3/11+4/9)=2×(1/7+3/11+4/稿敬蔽9﹚)/(1/7+3/11+4/9)=2
(6/11+2/7+8/9)÷(1/7+3/11+4/羡袜9) =2×(3/11+肆老1/7+兄雹激4/9)÷(1/7+3/11+4/9)=2