(5/(A)) and (7/(B)) are combined to get (20/(B)) and (7/(B)). It is known that A﹢B=45, then B=how much.
(5/(A))和(7/(B))通分得(20/(B))和(7/(B))，已知A﹢B=45，那么B=多少．
<gadget id="calculator">20 / 5</gadget>
<output>4</output>

<gadget id="calculator">1 + 4</gadget>
<output>5</output>

<gadget id="calculator">45 / 5</gadget>
<output>9</output>

<gadget id="calculator">4 * 9</gadget>
<output>36</output>

<result>36</result>