Question

简单，太简单的数学题了！！

在A=5.4321×1.2345与B=5.4322×1.2344中，较大的是哪一个，写出比较过程！
可不可以不用算的啊

Answer 1

B=5.4322*1.2344
=(5.4321+0.0001)*1.2344
=5.4321*1.2344+0.0001*1.2344
=5.4321*(1.2345-0.0001)+0.00012344
=5.4321*1.2345-5.4321*0.0001+0.00012344
=5.4321*1.2345-0.00054321+0.00012344
=A-0.00041977
因此：A大，B小。
两个因数的和相等的情况下，这两个因数的差越小，乘积越大。

Answer 2

两者作比，就是
5.4321×1.2345 / 5.4322×1.2344

一步一步的约去公约数,之后分子除以分母，结果是 0.99994 < 1

所以 5.4321×1.2345 < 5.4322×1.2344

Answer 3

A=5.4321×1.2345=(5.4322-0.0001)×(1.2344+0.0001)
=5.4322×1.2344+0.00054322-0.00012344+0.00000001
=5.4322×1.2344+0.00041979
A>B

Answer 4

A=5.4321×1.2345=6.70592745
B=5.4322×1.2344=6.70550768
A>B

Answer 5

A>B
直觉