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20×5.1+4.9×80=(20+80)×(5.1+4.9)
×
×
.(判断对错)
分析:根据小数四则运算的顺序,分别求出20×5.1+4.9×80与(20+80)×(5.1+4.9)的结果,然后再进一步解答.
解答:解:20×5.1+4.9×80
=102+392
=494;
(20+80)×(5.1+4.9)
=100×10
=1000;
494<1000;
所以,20×5.1+4.9×80<(20+80)×(5.1+4.9).
故答案为:×.
点评:本题关键是求出各个算式的结果,然后再比较解答.
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