一道分数计算题
问题描述：
一道分数计算题
用简便方法计算
3/4x1/5+3/4x2/5+0.75x3/5-3/4
答
3/4x1/5+3/4x2/5+0.75x3/5-3/4
=3/4x1/5+3/4x2/5+3/4x3/5-3/4
=3/4x(1/5+2/5+3/5-1)
=3/4x1/5
=3/20