If 3x-2x=5+2, then 9x-6x=how much.
若3x-2x=5+2，则9x-6x=多少．
<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">3 - 2</gadget>
<output>1</output>

<gadget id="calculator">7 / 1</gadget>
<output>7</output>

<gadget id="calculator">9 * 7</gadget>
<output>63</output>

<gadget id="calculator">6 * 7</gadget>
<output>42</output>

<gadget id="calculator">63 - 42</gadget>
<output>21</output>

<result>21</result>