解方程. 8x-3x=105 13.2x+9x=

解方程. 8x-3x=105 13.2x+9x=33.3 2x+1.5x=17.5 x-0.36x=16 6.2x-x=41.6 32.8+9x=118.3.

第1个回答  2015-01-10
8x-3x=105
       5x=105
    5x÷5=105÷5
        x=21;

   13.2x+9x=33.3
      22.2x=33.3
22.2x÷22.2=33.3÷22.2
          x=1.5;

  2x+1.5x=17.5
     3.5x=17.5
3.5x÷3.5=17.5÷3.5
        x=5;

    x-0.36x=16
      0.64x=16
0.64x÷0.64=16÷0.64
          x=25;

   6.2x-x=41.6
     5.2x=41.6
5.2x÷5.2=41.6÷5.2
        x=8;

     32.8+9x=118.3
32.8+9x-32.8=118.3-32.8
       9x÷9=85.5÷9
           x=9.5.