[2.25+0.75×(5/12×0.15)]×5/12简算

题目

[2.25+0.75×(5/12×0.15)]×5/12简算
怎么算?

答案

[2.25+0.75×(5/12×0.15)]×5/12
=[9/4+3/4(5/12×3/20)]×5/12
=3/4×(3+1/16)×5/12
=3/4×49/16×5/12
＝（49×5）/（16×16）
＝245/256