Fill in the appropriate operation symbol and small extension to make the equation 9 = 7

9-（9+9）/9=7

RELATED INFORMATIONS

1. It is known that a mathematical symbol △ holds the following equation: 2 △ 4 = 8, 5 △ 3 = 13, 3 △ 5 = 11, 9 △ 7 = 25, then 7 △ 3=______ ．
2. Fill in the operation symbols in the brackets to make the mathematical expressions equal. 1 () 2 () 3 () 4 () 5 = 200 If necessary, you can combine several numbers into one number, or add brackets. For example, write (1 + 23) * 4-5 on the left. The two sides of the formula must be equal
3. ）5 () 5 () 5 () 5 = 4; 9 () 9 () 9 () 9 () 9 = 18 fill in the operation symbols in brackets 9 () 9 () 9 () 9 = 18,
4. Fill them in with the notation 1 9 = 10 in order
5. 7 8 9 10 = 24 fill in the operation symbol can not change the position
6. 10 69 32 = 48, add bracket and operation symbol
7. Fill in appropriate operation symbols between 3, 3, 7 and 7 to make the result equal to 24
8. 3 3 7 7 fill in the operation symbol, so that the final answer is equal to 24 Can use add, subtract, multiply, divide, bracket, bracket, brace
9. How to add sign equal to 24 for 3, - 5,7, - 13
10. Add operation symbols or brackets between the following four numbers to make the result equal to 24. Use 9, 3, 7, 2,
11. 12 〕 37 〕 5 〕 6 〕 7 = 1998, fill in the appropriate operation symbol in 〕 to make the equation hold! Urgent!
12. 9 7 5 4 fill in the operation symbol to make the equation hold
13. Fill in the appropriate operation symbol to make the equation hold, 9 () 9 () 9 () 9 = 18 Only add and subtract symbols can be filled in
14. How to add operation symbol for 7 () 9 () 12 () 3 2 = 90
15. There are four groups of numbers below. Can you add the operation symbol to make the result all be 24? （1）2 3 4 6 （2）2 5 6 8 （3）1 2 3 10 （4）3 6 7 8
16. Fill in some operation symbols in 5 6 7 8 to make the result 24?
17. Fill in the operation symbol in 1 3 5 7 to make the result equal to 24
18. Add the operation symbol between 4, 4, 10 and 10 to make the result equal to 24
19. There are four rational numbers: 3, - 5,2, - 13. How to calculate 24
20. Four rational numbers 3,7, - 7, - 3 are operated by 24 points Give the formula