9/17×1/7+5/17÷7= 2/5÷(3/4+2/5 )= 简便计算
问题描述:
9/17×1/7+5/17÷7= 2/5÷(3/4+2/5 )= 简便计算
答
9/17×1/7+5/17÷7
=9/17×1/7+5/17×1/7
=(9/17+5/17)×1/7
=14/17×1/7
=2/17
2/5÷(3/4+2/5 )
=2/5÷23/20
=2/5×20/23
=8/23