<h2>The answer is "

".</h2>
Given:

To find:
n=?
Solution:

Therefore, the final answer of n is "
".
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brainly.com/question/322601
Answer:
Step-by-step explanation:
7x + 3 = 9x - 19
-2x + 3 = -19
-2x = -22
x = 11
DE= 7(11) + 3 = 77 + 3 = 80
EF = 9(11) - 19 = 99 - 19 = 80
80 + 80 = 160 for DF
A heptagon would have seven vertices
Answer: C
Step-by-step explanation: