问题 解答题
解方程
3.5X+0.5X=12.845x÷3=90(7-1.4)x+5=7.8.
答案

(1)3.5X+0.5X=12.8,

                4X=12.8,

             4X÷4=12.8÷4,

                 X=3.2;

(2)45x÷3=90,

        15x=90,

    15x÷15=90÷15,

          x=6.

(3)(7-1.4)x+5=7.8,

           5.6x+5=7.8,

         5.6x+5-5=7.8-5,

        5.6x÷5.6=2.8÷5.6,

                x=0.5.

单项选择题
单项选择题