When x=2.5, y=1.5, 2x-3y=how much.
当x=2.5，y=1.5时，2x-3y=多少．
<gadget id="calculator">2 * 2.5</gadget>
<output>5</output>

<gadget id="calculator">3 * 1.5</gadget>
<output>4.5</output>

<gadget id="calculator">5 - 4.5</gadget>
<output>0.5</output>

<result>0.5</result>