Final answer:
To calculate her yearly bonus, Robin should multiply 15 by -0.2 to account for the complaints and then add the result to 672. Performing this calculation shows that Robin's bonus would be $669.
Step-by-step explanation:
Robin's yearly bonus can be calculated by substituting x with the number of complaints in the expression -0.2x + 672. Since she received 15 complaints, she substituted 15 for x. Hence, the next step Robin should take is to multiply -0.2 by 15. This is the correct method of simplifying the expression given the information provided.
By performing this calculation, we find: (-0.2) × 15 = -3
Now, with this value, we can determine her bonus by adding 672 (her base bonus without any complaints) to the product of -0.2 and 15, which accounts for the deduction because of the complaints.
672 + (-3) = 669. Therefore, her bonus would be $669.