15.5-0.4(x+3)=3/4x-2/5(x-5)

问题描述:

15.5-0.4(x+3)=3/4x-2/5(x-5)

15.5-0.4x-1.2=0.75x-0.4x+2
14.3-0.4x=0.35x+2
0.75x=12.3
x=12.3÷0.75
= 16.4