解方程．1.9-140%x=1.2；23x+50%x=300；5-23x=13．

Question

解方程．        
1.9-140%x=1.2；             (2)/(3)x+50%x=300；              5-(2)/(3)x=(1)/(3)．

Answer 1

（1）1.9-140%x=1.2
  1.9-140%x+140%x=1.2+140%x
              1.9=1.2+140%x
          1.9-1.2=1.2+140%x-1.2
              0.7=140%x
        0.7÷140%=140%x÷140%
                x=0.5；

（2）(2)/(3)x+50%x=300
          (7)/(6)x=300
       (7)/(6)x÷(7)/(6)=300÷(7)/(6)
            x=(1800)/(7)；

（3）5-(2)/(3)x=(1)/(3)
 5-(2)/(3)x+(2)/(3)x=(1)/(3)+(2)/(3)x
        5=(1)/(3)+(2)/(3)x
     5-(1)/(3)=(1)/(3)+(2)/(3)x-(1)/(3)
       4(2)/(3)=(2)/(3)x
    4(2)/(3)÷(2)/(3)=(2)/(3)x÷(2)/(3)
          x=7．