Respuesta :

Let's review: 
Inverse Operations:
Inverse Operations are operations which undo each other!
I'll give the following Inverse Operations in this form.

Operation -> Inverse Operation

Addition -> Subtraction
Subtraction -> Addition

Multiplication -> Division
Division -> Multiplication

That's all of them we'll need to know to solve this problem! 

9x + 3 = 3x + 9

First Step!: Move all of the variables to once side (Numbers with x in them). (Prioritize the lower one so we won't need to work with negative numbers) Subtract 3x on both sides (Subtract, because the number is positive) 

9x - 3x + 3 = 3x - 3x + 9

3x - 3x = 0 

9x - 3x + 3 = 9 

Move the 3 to the right by subtracting it on both sides. 

9x - 3x + 3 - 3 = 9 - 3

3 - 3 = 0 
9 - 3 = 6

9x - 3x = 6 

Subtract like terms. (Just like you would subtract 9 - 3). Note that they are only like terms, because they both have the same variables (x) that are the same power (1).

6x = 6 

Divide 6 on both sides to get your answer.

6x/6 = 6/6 

The 6's cancel out and we are left with 1 on the left AND right, because 6/6 = 1. 

x = 1

Plug x in to check.

9(1) + 3 = 3(1) + 9 

9 + 3 = 9 + 3 

Those are definitely equal!

I hope that helped. If it did then consider giving me the brainliest answer. Thanks.
9x + 3=3x + 9....so 9x-3x=: 3 = -3x+9 and then you minus 9 from 3 and it equals to -3=-3x and then you divided -3 by -3 equals 
=1 negative divided by a negative "always" a positive. so the answer is  (positive one)