After multiplying the former term of a ratio by 3 and adding 12 to the latter term, the ratio remains unchanged. What is the posterior term of this ratio
一个比的前项乘3，后项加12后，比值不变．这个比的后项是多少
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<result>6</result>