1.5x+3x=6 x=4/3
2x-1.5x=1.9 x=3.8
0.54 x-4.5*6=45 题意不清楚 X=133.33
7x-0.4=0.3 x=10
8x+5x=65 x=5
0.9x-3*1.2=7.2 x=12