LZ: 3x/4-0.4=1x/2+0.3
解:方程两边同时乘以 4
得 3x-1.6=2x+1.2
3x=2x+1.2+1.6
3x-2x=2.8
∴ x=2.8
3/4x-0.4=1/2x+0.3
1/4x=0.7
x=2.8
依题意得3/4x-0.4=1/2x+0.3
3x-1.6=2x+1.2
x=2.8
(0.75-0.5)x=0.3-0.4
0.25x=-0.1
x=-0.4