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Answer:
Answer choice C) 3a-3
Step-by-step explanation:
Your perimeter is of (10a-6). The first step would be multiply 2a by 2 since you have to sides. Which would give you to 4a. Next you will have to subtract 4a from (10a-6). This would give you 6a-6. Finally divide by two and you will get 3a-3.