It is known that the sum of A and B is 8.5, and (2/3) of A is equal to (3/4) of B. What is the difference between A and B?
已知甲乙两数的和是8.5，甲数的(2/3)等于乙数的(3/4)，甲乙两数的差是多少．
<gadget id="calculator">9 + 8</gadget>
<output>17</output>

<gadget id="calculator">8.5 / 17</gadget>
<output>0.5</output>

<gadget id="calculator">9 - 8</gadget>
<output>1</output>

<gadget id="calculator">0.5 * 1</gadget>
<output>0.5</output>

<result>0.5</result>