Hello!
An exponent's basic formula is: . This means that x is being multiplied by itself y times. For example, if it were , 2 would be multiplied by itself 3 times, to make 2 * 2 * 2, or 8.
For the integer 9, it is a square number. This means that a number times itself = 9. More specifically, 3 times 3, or itself, is equal to 9. This means that x is 3, and y is 2, as 3 is being multiplied by itself, and 2 is the amount of times it is multiplied by itself.
This gives us our final equation:
Hope this helps!