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ORThe 19th term of an AP is equal to three times its oth term. if ts 9th term is 19, find the APnE Four vears hence the age of the father will |
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Answer» Let in an AP first term = a Common difference = d9th term = 19a + 8d = 19----(1)19th term =3*(6th term)a + 18d = 3(a+5d)a + 18d = 3a+15d0 = 3a+15d-a-18d2a - 3d = 0-----(2)subtract (2) from 2*(1)-19d = -38d = 2substitute d=2 in (1)a=3 Therefore a=3, d=2Required AP is3, 5, 7, 9,.... |
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