In the equation ((2(3/5)-(8.5-□)/3.5)/(1/(3.05+4(9/20))))=2, □ represents a number, then, □=how many ．
在等式((2(3/5)-(8.5-□)/3.5)/(1/(3.05+4(9/20))))=2中，□表示一个数，那么，□=多少．
<gadget id="calculator">17 / 2</gadget>
<output>17/2 = around 8.5</output>

<gadget id="calculator">49 / 6</gadget>
<output>49/6 = around 8.166667</output>

<gadget id="calculator">(17/2) - (49/6)</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>