Question

which is the 5th term of A.P. 21,18,15....?​

Answer 1

Answer:

9

Step-by-step explanation:

tn=a+(n-1)d

d=t2-t1=18-21= -3

n=5

tn=21+(4)-3

tn=21-12

tn=9

hope it helps

Answer 2

Answer:

9

Step-by-step explanation:

5th term of Arithmetic progression

= dn+ ( f - d )

d = common difference

=18 - 21 = -3

n = term

f = first term

then,

5th term = dn + (f- d)

= -3×5 + ( 21 - -3 )

= -15 + 24

= 9