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Question
Complete the following activity to find the 19th term of an A.P. 7, 13, 19, 25, ........ :
Activity:
Given A.P. : 7, 13, 19, 25, ..........
Here first term a = 7; t19 = ?
tn + a + `(square)`d .........(formula)
∴ t19 = 7 + (19 – 1) `square`
∴ t19 = 7 + `square`
∴ t19 = `square`
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Solution
Given, A.P. : 7, 13, 19, 25, ..........
Here, first term a = 7; t19 = ?
tn + a + (n – 1)d .........(formula)
∴ t19 = 7 + (19 – 1)6
∴ t19 = 7 + 108
∴ t19 = 115
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