No, you found the sum of the absolute values. The rule for adding numbers of unlike sign is: Find the difference of the absolute values (not the sum); then attach the sign of the number with the larger absolute value.
The difference of the two numbers is found by subtracting the smaller from the larger. In our problem, ( − 9) + ( + 6), the absolute values are 9 and 6, and the difference of the absolute values is 3 (since 9 − 6 = 3). So all we have to do is to attach the sign of the number, either ( − 9) or ( + 6), that has the larger absolute value to this difference and we have the right answer.
