Convert (5/14), (3/7), (7/12) into fractions with the same denominator, what is the smallest denominator.
把(5/14)，(3/7)，(7/12)化成同分母分数，分母最小是多少．
<gadget id="calculator">12 * 7</gadget>
<output>84</output>

<result>84</result>