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Example 14 The eighth term of an A.P. is half of its second term and 11th term evcevone third of fourth term by 1. Find the 15th term. |
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Answer» a + 7d = a + d/22a + 14d = a + da = -13da +10d = 1/3(a +3d) + 1a +10d -1 = 1/3(a + 3d)3(a + 10d -1) = a +3d3a + 30d -3 = a+ 3d2a + 27d =32(-13d) + 27d =3(since a = -13d)-26d + 27d = 3d = 3a= -13da = -39a + 14d = -39 + 42hence a15 =3 |
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