Solve the equation: (1+(1/3))x=28.
解方程：(1+(1/3))x=28．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 + (1/3)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">28 / (4/3)</gadget>
<output>21</output>

<result>21</result>