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Mathematics
Problem
The infinite series
∑
n
=
1
∞
(
k
+
2
)
(
−
3
)
1
−
n
\displaystyle\sum_{n=1}^{\infty}(k+2)(-3)^{1-n}
n
=
1
∑
∞
(
k
+
2
)
(
−
3
)
1
−
n
converges to
18
18
18
. What is the value of
k
k
k
? a)
10
10
10
b)
22
22
22
c)
−
6
-6
−
6
d)
12
12
12
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