Solve the equation: (6/7)x+(8/7)x=28.
解方程：(6/7)x+(8/7)x=28．
<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">8 / 7</gadget>
<output>8/7 = around 1.142857</output>

<gadget id="calculator">(6/7) + (8/7)</gadget>
<output>2</output>

<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<result>14</result>