Given that a☺b=4*a-5*b, find (5☺3)☺2.
已知a☺b=4*a-5*b求(5☺3)☺2．
<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">20 - 15</gadget>
<output>5</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

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

<result>10</result>