The ratio of the numbers A and B is 9:7, the number A is multiplied by 5 times, and the number B is added to keep the ratio unchanged.
甲、乙两数的比是9：7，甲数扩大原来的5倍，乙数加上多少，比值不变．
<gadget id="calculator">7 * 5</gadget>
<output>35</output>

<gadget id="calculator">35 - 7</gadget>
<output>28</output>

<result>28</result>