(0.4x+0.9)/0.5--(0.03+0.02x)/0.03=(x--5)/2
(4x+9)/5-(3+2x)/3=(x-5)/2,
6(4x+9)-10(3+2x)=15(x-5),
24x+54-30-20x=15x-75,
(24-20-15)x=-75-54+30,
-11x=-99,
x=9.
2(0.4x+0.9)+(100/3)(0.03+0.02x)=(x+5)/2
12(0.4x+0.9)+200(0.03+0.02x)=3x+15
4.8x+10.8+6+4x=3x+15
8.8x+16.8=3x+15
5.5x=-1.8
x=-(18/55)
(0.4x+0.9)/0.5--(0.03+0.02x)/0.03=(x--5)/2
4x/5+9/5-1-2/3x=x/2-5/2
x=9
(0.4x+0.9)/0.5--(0.03+0.02x)/0.03=(x--5)/2
4x/5+9/5-1-2/3x=x/2-5/2
x=9
(0.4x+0.9)/0.5+(x-5)/2=(0.02x+0.03)/0.03
推导出(4x+9)/5+(x-5)/2=(2x+3)/3
继续
24x+54+15x-75=20x+30
所以
19x=51
x=51/19
(0.4x+0.9)/0.5-(0.03+0.02x)/0.03=(x-5)/2
(0.4x+0.9)/0.5-(x-5)/2-(0.03+0.02x)/0.03=0
4x/5+9/5-x/2+5/2-1-2x/3=0
即x=9