Question

Determine the ap whose fifth term is 19 and difference of the 8th term from the 13th term is 20

Answer 1

a13-a8=20
a+12d-(a+7d) =20
d = 4----©

a15=19
a+14d=19----®
Sub© in ®
a+56=19
a=-37
A.P is -37,-33,-29,...