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Recall that the slope is the "average rate of change" of any function.

Havent done this in years but i think it would just be 12
The answer should be 91 because for your total perimeter you add all the sides. So you already have your length of 75 which counts as 2 sides and equals up to 150. after you subtract your two sides from your perimeter you get 182. you then divide 182 by 2 to get your two remaining sides which gives you 91.