(0.25+0.125)/(0.75*0.4)（是要简便运算的）
问题描述：
(0.25+0.125)/(0.75*0.4)（是要简便运算的）
答
(0.25+0.125)/(0.75×0.4)
=(0.125×2+0.125)/(0.125×2×3×0.4)
=[0.125×(2+1)]/(0.125×2×3×0.4)
=(2+1)/(2×3×0.4)
=3/(2×3×0.4)
=1/(2×0.4)
=(1×5)/(2×0.4×5)
=5/4