To find the 10th term of the series 3x3x, tx ..
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Answer:
How do you find the 10th term of an arithmetic series?
The 3rd term of an arithmetic series, A, is 19.
The sum of the first 10 terms of A is 290.
Find the 10th term of A.
Use
S
n
=
n
2
(
2
a
+
(
n
−
1
)
d
)
Algebra
1 Answer
1s2s2p
May 18, 2018
a
10
=
47
Explanation:
So, we know that:
a
+
2
d
=
19
290
=
5
(
2
a
+
9
d
)
a
+
2
d
=
19
58
=
2
a
+
9
d
We now use substituion to find the 10th term:
a
+
2
d
=
19
,
a
=
19
−
2
d
2
a
+
9
d
=
58
2
(
19
−
2
d
)
+
9
d
=
58
38
−
4
d
+
9
d
=
58
5
d
=
20
d
=
4
Putting this into 2 gives us:
a
+
8
=
19
a
=
11
a
10
=
11
+
9
(
4
)
=
47
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