x-3/10*x -(3/10*x -80 )=440此方程怎么解

问题描述:

x-3/10*x -(3/10*x -80 )=440此方程怎么解

900可以说一下解的过程吗?谢谢x-3/10*x -(3/10*x -80 )=x-3/10*x -3/10*x +80=2/5x+80=440则:0.4x=360故:x=900