open computing. Use the knowledge of the four mixed operations you have learned to calculate 24 with 3, 4, 5, and 7 cards. How many different algorithms do you have? (Only lists the formula, the number is not limited)
开放性计算．利用所学的四则混合运算知识，用3、4、5、7四张牌算出24，你有几种不同的算法？(只列出算式，个数不限)
<result>5</result>