0.75X15+4.5X2.5=多少 3.6X31.4+43.9X64.4=多少

来源：百度知道 编辑：UC知道 时间：2024/07/05 06:08:13
用简便的!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
写出来,最好简便,都写出来,不要说什么意思!

把所有的小数都化成分数,0.75,4.5,2.5,分别变成3/4,9/2,5/2,原式变成3/4*15+9/2*5/2,9/2*5/2=3/4*15,就化简了

把所有的小数都化成分数,3/4*15+9/2*5=45/4+45/4=45/2；
第二题我想不到简便方法
3.6X31.4+43.9X64.4=113.04+124112.324=124225.364

0.75X15+4.5X2.5=11.25+11.25=22.5
3.6X31.4+43.9X64.4=113.04+124112.324=124225.364

0.75*15+4.5*2.5=2.5*0.3*15+4.5*2.5=2.5*4.5+4.5*2.5=2.5*4.5*2=2.5*9=22.5