7/15×3/8+1/15×7/16+1/15×3又1/2
＝7/15×3/8+1/15×7×1/16+1/15×7/2
＝7/15×3/8+7/15×1/16+7/15×1/2
＝7/15×﹙3/8+1/16+1/2﹚
＝7/15×﹙6/16+1/16+8/16﹚
＝7/15×15/16
＝7/16
7/15*3/8+1/15*7/16+1/15*3又1/2
=7/15*3/8+7/15*1/16+7/15*1/2
=7/15*(3/8+1/16+1/2)
=7/15*15/16
=7/16
7/15*3/8+1/15*7/16+1/15*3又1/2
=7/15*3/8+7/15*1/16+7/15*1/2
=7/15*（3/8+1/16+1/2）
=7/15*15/16
=7/16
7/15*3/8+1/15*7/16+1/15*3又1/2
=7/15x3/8+7/15x1/16+7/15x1/2
=7/15x(3/8+1/16+1/2)
=7/15x15/8
=7/8
祝学习进步，望采纳，不懂的欢迎追问...
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024