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Class 10 (Old)

Course: Class 10 (Old) > Unit 5

Lesson 4: Sum of first n terms of an AP
Math
Class 10 (Old)
Arithmetic progressions
Sum of first n terms of an AP
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Sum of n terms (intermediate)

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Problem

The sum of n terms of an arithmetic progression is given by:
S, start subscript, n, end subscript, equals, start fraction, 7, divided by, 2, end fraction, n, squared, plus, start fraction, 17, divided by, 2, end fraction, n
Find the fifth term, a, start subscript, 5, end subscript.
a, start subscript, 5, end subscript, equals
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3, slash, 5
  • a simplified improper fraction, like 7, slash, 4
  • a mixed number, like 1, space, 3, slash, 4
  • an exact decimal, like 0, point, 75
  • a multiple of pi, like 12, space, start text, p, i, end text or 2, slash, 3, space, start text, p, i, end text
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