Question

what step by step explanation...​

Answer 1

Answer:

d=8/9

Step-by-step explanation:

a=10

last term= (l)=28 =an

sn=n/2 (a+l)

190=n/2 (10+28)

=n/2 ×38

190=n×19

n=190/19

n=10

a.p formula

an=2a+(n-1)d

28=2×10+(10-1)d

28=20+9d

28-20=9d

8=9d

d=8/9