奥数(0.75x42.7+57.3-0.573x25)/3x7972=?

显示全部楼层 · 2012-10-22 20:13:25

原题=(0.75x42.7+57.3*（0.75+0.25）-0.573x25)/3x7972
=(0.75x42.7+57.3*0.75+57.3*0.25-0.573x25)/3x7972
=(0.75x42.7+57.3*0.75+0.573*0.25*100-0.573x0.25*100)/3x7972
=(0.75*100)/3*7972
=75/3*7972如果原题是7972在分数线下，则答案为25/7972如果原题是7972在分数线外，则答案为25*7972=199300...

千问 · 2012-10-22 20:13:25

(0.75x42.7+57.3-0.573x25)/3x7972=[75*0.427-(1-0.427)*25+57.3]/3*7972=[0.427*100-25+57.3]/3*7972=[42.7+57.3-25]/3*7972=25*7972=199300...

千问 · 2012-10-22 20:13:25

解：(0.75x42.7+57.3-0.573x25)/3x7972=[0.75×（100-57.3）+57.3-57.3×0.25]/3×7972=[75-57.3×（0.75+0.25-1）]/3x7972=75/3x7972=25x7972=199300...

千问 · 2012-10-22 20:13:25

(0.75*42.7+57.3-57.3*100*0.25)/3*7972=0.75*(42.7+57.3)/3*7972=25*7972=199300...