a☆b=5a+4b. Then if 8☆x=68． Then x = how much.
a☆b=5a+4b．那么如果8☆x=68．则x=多少．
<gadget id="calculator">68 - 40</gadget>
<output>28</output>

<gadget id="calculator">28 / 4</gadget>
<output>7</output>

<result>7</result>