Question

What is the general term for the AP with t8=6 and t20= -30

Answer 1

Answer:

27,24,21,18,15,12,9,6,...........

Step-by-step explanation:

we know that the general term of an ap can be written as

a+(a+d)+(a+2d)+(a+3d)+...........+(a+Nd)

now given:

t8= 6. T20=-30

t8= a+7d

6= a+7d-------------> (1. EQ.

also we know that

T20 = -30

i.e

-30 = a+ 19d------------>(2.eq

from EQ 1 and 2

-12d = 36

d= -3

now put the value of d in any EQ.

6=a+7(-3)

6= a-21

a= 27

now the ap is

27,24,21,18,...............