Which term of AP:121,117,113....... is its first negative term?

1.	Which term of AP:121,117,113....... is its first negative term?
Answer» a = 121d = -4let an= 0thenan = a + (n-1)d=> 0 = 121 + (n-1)(-4)=> 0 = 121 - 4n + 4=> 4n = 125=> n = 125/4=> n = 31.25as n must be natural number then n= 3232nd term is First negative number.a32 = 121 + (31)-4= 121 - 124 = -3

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