Question

find the 10th term of an ap 21, 18, 15,_______ -30​

Answer 1

Answer:

a=21

d=-3

a(10)=a+(n-1)d

=21+(10-1)-3

21+(9)×-3

21-27=-6

Answer 2

Step-by-step explanation:

a = 21

a+d= 18

d=(a+d-a)

d=18-21

d= -3

calculating a10

=a+9d

=21+9(-3)

=21+(-27)

= -6