A) is not a function because you have two X values of -1
B) is not a function because you have two X values of -2
C) is not a function because you have two X values of 0
D) This is a function because all X values are different.
Answer:
<em>900° </em>
Step-by-step explanation:
The interior angles sum = 180° ( n - 2 )
~~~~~~~~
n = 7
180° ( 7 - 2 ) = <em>900°</em>