解方程. 50%x+x=150 x÷10%=300 3%x+20=60×5/6 4/5x-12.6=40%x.

问题描述:

解方程.
50%x+x=150    
x÷10%=300
3%x+20=60×

5
6

4
5
x-12.6=40%x.

(1)50%x+x=150,
           1.5x=150,
      1.5x÷1.5=150÷1.5,
              x=100;
(2)x÷10%=300,
     x÷0.1=300,
x÷0.1×0.1=300×0.1,
          x=30;
(3)3%x+20=60×

5
6

   0.03x+20=50,
0.03x+20-20=50-20,
      0.03x=30,
0.03x÷0.03=30÷0.03,
          x=1000;
(4)
4
5
x-12.6=40%x,
     0.8x-12.6=0.4x,
0.8x-12.6-0.4x=0.4x-0.4x,
     0.4x-12.6=0,
0.4x-12.6+12.6=0+12.6,
          0.4x=12.6,
     0.4x÷0.4=12.6÷0.4,
             x=31.5.