Answer:
C=30
Step-by-step explanation:
Supposing that we have the lines
x+2=10y
and
3x+6=Yc.
Note that dividing by 3 the second line can be rewritten as
x + 2= Y c/3.
Remember that a line is written as
, in our case, both lines have
and
. Therefore, in orther that the two lines are equal, we need that
, hence 
7n-84 would be your correct answer, 7 times n is 7n. 12 times 7 is 84 so therefore your answer would be 7n-84
4y + 228 = 352
4y = 352 - 228
4y = 124
--- ----
4 4
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| y = 31 |
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hope this helps
The given sequence is:

a(2)=1
a(3)=3
a(4)=9
We are to find the average rate of change between n=3 and n=4 for the given function.
Average rate of change =

So the average rate of change for the given function from n = 3 to n = 4 is 6