If "2a+1" is equal to 8, what is "4a+1" equal to
如果"2a+1"等于8，那么"4a+1"等于多少
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">4 * (7/2)</gadget>
<output>14</output>

<gadget id="calculator">14 + 1</gadget>
<output>15</output>

<result>15</result>