In 3:4, if the latter term of the ratio is increased by 8, how much should the former term be increased to keep the ratio constant
在3：4中，如果比的后项增加8，要使比值不变，前项应增加多少
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">9 - 3</gadget>
<output>6</output>

<result>6</result>