Answer:
10n^2 + 2n + 16
Step-by-step explanation:
Rectangles have the same length and same width. So we can deduce that the top side is 5n^2 - 1, and the left side is n + 9.
Now all we need to do is add all 4 sides up:
(5n^2 - 1) + (5n^2 - 1) + (n + 9) + (n + 9)
or
2(5n^2 - 1) + 2(n + 9)
= 10n^2 - 2 + 2n + 18
= 10n^2 + 2n + 16
