Question

20th term from the last term of the AP 21, 18,15, …. , -72 is

Answer 1

Step-by-step explanation:

tn=a+(n-1)d

t20=21+(20-1)-3

t20=21+19x-3

t20=21-57

t20=-36

Answer 2

Answer:

- 15

Step-by-step explanation:

to find the last 20th term let  us take the ap in reverse so

-72,......,15,18,21 is the ap now

here a= -72    d=3     n=20     an=?

an=a+(n-1)d

an=  -72  + (20-1)3

   =  -72 +19x3

   =  -72 +57

   =  -15

thus -15 is the last 20th term from last

pls mark this as Brainliest