7.8x2.5+78×0.75简算:
7.8x2.5+78×0.75
=78x0.25+78x0.75
=78x(0.25+0.75)
=78x1
=78
分析:本题主要考查乘法分配律和结合律。
原式=78*0.25+78*0.75
=78*(0.25+0.75)
=78*1
=78
=7.8×10×(2.5÷10)+78×0.75
=78x0.25+78x0.75
=78x(0.25+0.75)
=78x1
=78
原式=78×0.25+78×0.75=78×(0.25+0.75)=78×1=78