find the sum of first51 terms of an ap whose second and third term are 14 and 18 respectively
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Step-by-step explanation:
a(2) = 14
a + d = 14 --------(1)
a(3) = 18
a + 2d = 18 ---------(2)
समी. (2) - (1) से
d = 4
समी.(1) से
a + 4 = 14
a = 10
51 पदों का योग = 51/2 {2(10)+(51-1)4}
= 51/2 {20 + 200}
= 51/2 * 220
= 51 * 110
= 5610
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