（x-2)/0.2 - （0.1x-0.1）/0.05=3 1/100[（x-2)/0.2 - （0.1x-0.1）/0.05]=3/100(x-2)/20 -(0.1x-0.1)/5=3/300x/20 -0.1 - 0.02x+0.02=0.030.05x-0.1-0.02x+0.02=0.030.03x+0.01=0.033x+1=3x=2/3
