If ab=5, ab=-6, find the value of a**2+b**2.
若a-b=5，ab=-6，求a**2+b**2的值．
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">2 * (-6)</gadget>
<output>-12</output>

<gadget id="calculator">25 + (-12)</gadget>
<output>13</output>

<result>13</result>