0.5x+4x×0.1=27.9怎么解

问题描述:

0.5x+4x×0.1=27.9怎么解

0.5x+0.4x=27.9
(0.5+0.4)x=27.9
0.9x=27.9
x=27.9/0.9
x=3.1