问题
填空题
1997×0.71+11×7
|
答案
1997×0.71+11×7
+2222×0.291 4
=1997×0.71+11×7.25+2222×0.29
=1997×0.71+11×7.25+1997×0.29+225×0.29
=1997×(0.71+0.29)+225×0.29+10×7.25+7.25
=1997×(0.71+0.29)+225×0.29+72.5+0.29×25
=1997+72.5+0.29×(225+25)
=1997+72.5+72.5
=2142
故填:2142.