If the 7th time 7th term of an ap is equal to 11times 1th term of an ap then 18 th term will be
Answers
Answered by
13
hey!
let first term be a and common difference be d.
since an = a + (n-1)d
=) a7 = a + (7-1)d = a + 6d
=) a11 = a + (11-1)d = a + 10d
According to ur question ;
=) 7(a7) = 11(a11)
=) 7(a+6d) = 11(a+10d)
=) 7a + 42d = 11a + 110d
=) 7a - 11a = 110d - 42d
=) - 4a = 68d
=) - a = 17d
Since a18 = a + (18-1)d
= a + 17d
= a + (-a)
= 0.
hope it helps you!
let first term be a and common difference be d.
since an = a + (n-1)d
=) a7 = a + (7-1)d = a + 6d
=) a11 = a + (11-1)d = a + 10d
According to ur question ;
=) 7(a7) = 11(a11)
=) 7(a+6d) = 11(a+10d)
=) 7a + 42d = 11a + 110d
=) 7a - 11a = 110d - 42d
=) - 4a = 68d
=) - a = 17d
Since a18 = a + (18-1)d
= a + 17d
= a + (-a)
= 0.
hope it helps you!
Similar questions