5/7x2/3x1/4=5/7x1/6=5/42谢谢,请采纳
5/7×2/3×1/4=5/告迟7×(2/宴仔3×1/4)=5/7×1/6=5/晌友汪42
5/7×2/3×1/4 =5/7×1/3×1/2=5/42
5/7x2/3x1/4=10/21x1/4=5/42
稚军旅潦岩领导下饶