Let a, b, c, d be 4 different numbers randomly selected from 1, 2, 3, ..., 9, so that ((a+b)/(c+d)) is an integer, then ( How many values of (a+b)/(c+d)) are there?
设a、b、c、d是从1，2，3，…，9中任意选出的4个不同的数字，使得((a+b)/(c+d))是一个整数，则((a+b)/(c+d))的值有多少个．
<gadget id="calculator">9 + 6</gadget>
<output>15</output>

<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<result>5</result>