9 + 3 = ? + 9

9 + 3 = 12

Since both sides equal the same thing, the question mark is a 3
9 +3 = 3 + 9

Thank you so much:-)

To find the value of the missing number in the equation 9 + 3 = ? + 9, we can start by simplifying the left side.

9 + 3 equals 12.

So, the equation becomes: 12 = ? + 9.

To isolate the missing number on one side of the equation, we need to subtract 9 from both sides.

12 - 9 equals 3.

Thus, the missing number in the equation is 3.

To verify the answer, you can substitute 3 back into the equation: 9 + 3 = 12, which is true.