8/25*2/7+8/25*3/7+17/25*5/7=()(用简便方法计算)

问题描述:

8/25*2/7+8/25*3/7+17/25*5/7=()(用简便方法计算)

8/25*2/7+8/25*3/7+17/25*5/7
=8/25x(2/7+3/7)+17/25x5/7
=8/25x5/7+17/25x5/7
=5/7x(8/25+17/25)
=5/7x1
=5/7