(1/2) of x is 21 more than 39, find x.
x的(1/2)比39多21，求x．
<gadget id="calculator">39 + 21</gadget>
<output>60</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">60 / (1/2)</gadget>
<output>120</output>

<result>120</result>