Question

0.25x27+0.75x25+2,怎么算？

Answer 1

解答如下:
0.25×27+75×0.25+2
=0.25×（27+75）+2
=0.25×100+2
=25+2
=27
因数×因数=积
一个因数扩大到它原来的100倍，要使积不变，另一个因数要缩小到它原来的100倍。

Answer 2

解：0.25×27+0.75×25+2
=0.25×27+75×0.25+2
=0.25×（27+75）+2
=0.25×102+2
=0.25×（100+2）+2
=0.25×100+0.25×2+2
=25+0.5+2
=27.5