Question

find the 27th term ofA.P. 9,4,-1,-6,-11...​

Answer 1

Step-by-step explanation:

d=T2-T1

d=4-9

d=-5

then,

T27=a+26d

=9+26+(-5)

=-81

Answer 2

Given A.P = 9,4,-1,-6,-11,.....

where a = 9

a2 = 4

a3 = -1

a4 = -6

a5 = -11

and so on.....

a ( first term ) = 9

d ( common difference ) = a2 - a = 4 - 9 = -5

n ( no. of term) ( to find) = 27

We know that,

an = a + (n-1) d

$an = 9 + (27 - 1)( - 5) \\ = 9 + (26)( - 5) \\ = 9 + ( - 130) \\ = 9 - 130 \\ = - 121$

The 27th term of the given A.P is -121