According to the way I learned it, you would add 9 since you are subtracting it and since it is subtracted, it would be considered a negative number so it would cancel out if you add 9. You would also add 9 to -93 which would give you -84. Bring it down and it will become -7x=-84. Divide both sides by -7, canceling out -7, and -84 divided by -7 is 12. Since they are both negative, you make it positive according to integer rules and therefore, x=12.
