3. If the common difference of an AP is 3, then what is a18-a13
Question
3. If the common difference of an AP is 3, then what is a18-a13
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Mathematics
10 months
2021-07-19T04:49:58+00:00
2021-07-19T04:49:58+00:00 1 Answers
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Answer:
Given, common difference of the AP,
d=5
We know that,
a
n
=a
1
+(n−1)d
Then,
a
18
=a
1
+17×d
a
13
=a
1
+12×d
Solving the two equations,
a
18
−a
13
=a
1
+17d−a
1
−12d
a
18
−a
13
=5d,
Substituting d=5,
a
18
−a
13= 25