I want to make the numbers 1,2,...,9 using exactly three copies of the number 9 and the following actions: addition, subtraction, multiplication, division, squaring, taking square roots, and other action.

How can we make the numbers 5 or 7?

For example, we can make the below numbers using exactly three copies of the number 9.

- 1=√9×√99
- 2=9+99
- 3=√9×99
- 4=99+√9
- 5=?
- 6=9+9√9
- 7=?
- 8=9−99
- 9=9+9−9.
Now, how can we make the numbers 5 and 7?

**Answer**

5=√9!−99,7=√9!+99

**Attribution***Source : Link , Question Author : elham , Answer Author : fuglede*