Let
denote the given sequence with
:

Let
be the sequence of the forward differences of
, so that
for
:

follows an arithmetic progression with a difference of 2 between terms, so that

Then we have

so that
is given recursively by

By substitution, we can try to find a pattern:




and so on, with the general pattern

and since
we can write this as



Recall that

Then

Answer:
A
Step-by-step explanation:
when the line is solid its greater, smaller or equal to
when the line is dashed its greater or smaller
When the shade is above the y is greater
When the shade is coming from down its less than
A(t) 800 0.057t
A(14) = 1,678.43
Total weight = 50 lb
x = number of 3-lb weights
y = number of 10-lb weights
weight of 3-lb weights = 3x
weight of 10-lb weights = 10y
total weight = 3x + 10y
equation
3x + 10y = 50