Just set the perimeter equation equal to each other and put the values in that you know and solve
Answer:
|x |-7 = -5 ( x = -3 )
Step-by-step explanation:
Answer:

Step-by-step explanation:
Whenever you are adding exponents that have the same base (in this case the base is 9), you simply add the exponents. The base will stay the same because you are just adding the exponents

So, your answer is 
Hope this helps!