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

1.	Which term of AP 121,117,113.................is its first negative term
Answer» a = 121d = -4let an= 0thenan\xa0= 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\xa0term is First negative number.a32\xa0= 121 + (31)-4= 121 - 124 = -3

Discussion