If

is the common difference between terms in the sequence

, then



...

You're told that

(the sum of the first 16 terms in the sequence, presumably). Well, we know that


Recall that

so that we have

So we get
Answer:
135
Step-by-step explanation:
Two supplement angles add up to equal 180 degrees.
So, (45+x=180)
180-45=x
135=x
Answer:
20
Step-by-step explanation:

8+(x/-9)=9 subtract 8
x/-9= 1 multiply by -9
x= -9