5x－4.9x＝0.31
0.1x＝0.31
x＝0.31÷0.1
x＝31
3.4÷x＝4.8÷24
3.4＝0.2x
x＝3.4÷0.2
x＝17
8－3(x＋0.2)＝0.8
8－3x－0.6＝0.8
-3x＝-6.6
x＝-6.6÷(-3)
x＝2.2
不懂可追问!