Solve the equation; 7x-8=5x+12.
解方程；7x-8=5x+12．
<gadget id="calculator">8 + 12</gadget>
<output>20</output>

<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>