large whale has a head length of 3 meters, a body length equal to the head length plus a tail length, and a tail length equal to the sum of the head length plus half the body length. How long is this big whale in meters?
一条大鲸鱼，头长3米，身长等于头长加尾长，尾长等于头长加身长的一半的和．这条大鲸鱼全长多少米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 * (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">3 + (3/2)</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(9/2) / (1/2)</gadget>
<output>9</output>

<gadget id="calculator">3 + 3 + 9 + 9</gadget>
<output>24</output>

<result>24</result>