问题 解答题

解方程.

6x+4x=1.8×4                             8.6-(x+2)=1.8

(x-3.8)×0.7=3.36                        1.8×2.5+0.5x=8.5.

答案

(1)6x+4x=1.8×4,

           10x=7.2,

       10x÷10=7.2÷10,

             x=0.72;

(2)8.6-(x+2)=1.8,

 8.6-(x+2)+(x+2)=1.8+(x+2),

                 8.6=x+3.8,

           x+3.8-3.8=8.6-3.8,

                   x=4.8;

(3)(x-3.8)×0.7=3.36,

      0.7x-3.8×0.7=3.36,

          0.7x-2.66=3.36,

     0.7x-2.66+2.66=3.36+2.66,

               0.7x=6.02,

          0.7x÷0.7=6.02÷0.7,

                  x=8.6;

(4)1.8×2.5+0.5x=8.5,

          4.5+0.5x=8.5,

      4.5+0.5x-4.5=8.5-4.5,

              0.5x=4,

         0.5x÷0.5=4÷0.5,

                 x=8.

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