(3/4) of number A is equal to (3/5) of number B (both A and B are not 0). The sum of A and B is (18/19). What is A's number?
甲数的(3/4)等于乙数的(3/5)(甲、乙均不为0)，甲、乙两数的和是(18/19)，甲数是多少．
<gadget id="calculator">18 / 19</gadget>
<output>18/19 = around 0.947368</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(18/19) * (4/9)</gadget>
<output>8/19 = around 0.421053</output>

<result>8/19 = around 0.421053</result>