The newly defined operation a△b=3a-2b, then 5△4=how much.
新定义运算a△b=3a-2b，那么5△4=多少．
<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<gadget id="calculator">15 - 8</gadget>
<output>7</output>

<result>7</result>