(0.03+0.02x)/0.03+(x-5)/2=(0.4x+0.9)/0.5
1+2x/3+(x-5)/2=4x/5+9/5
30+20x+15x-75=24x+54
35x-24x=54+45
11x=99
x=9
(0.03+0.02x)/0.03+(x-5)/2=(0.4x+0.9)/0.5
1+2/3x+x/2-5/2=4/5x+9/5
2/3x+x/2-4/5x=9/5+5/2-1
11/30x=33/10
x=33/10×30/11
x=9
1+2x/3+x/2-2.5=4x/5+9/5
7x/6-1.5=4x/5+1.8
(35x-24x)/30=3.3
11x=99
x=9