The natural numbers A and B satisfy (1/(A))-(1/(B))=(1/54), and A:B=2:9, find the value of A+B.
自然数A，B满足(1/(A))-(1/(B))=(1/54)，且A：B=2：9，求A+B的值．
<gadget id="calculator">2 + 9</gadget>
<output>11</output>

<gadget id="calculator">11 * 21</gadget>
<output>231</output>

<result>231</result>