The 8th term of an AP is -23 and its 12th term is -39. Find the AP.

8th term =-23------1
12th term =-39----2
so, in the first equation
given- n=8
(a+(n-1)d)=-23
a+(8-1)d=-23
a+7d= -23-------1

in the second equation
given= n=12

(a+(n-1)d)=-39
a+(12-1)d=-39
a+11d= -39-------2
subtracting 1 and 2

a+7d= -23
a+11d= -39
- - +
_____________
-4d=16
d= -16/4
d= -4

putting in 1
a+(7x-4)= -23
a +(-28)= -23
a= 28-23
a=5