Answer:
B) 72
Step-by-step explanation:
The n-th term of an arithmetic sequence An = a1 + (n - 1) d
Given :
a28 = 423/4 and d = 5/4
So
a28 = a1 + (28 - 1)5/4
Now plug in a28 = 423/4
423/4 = a1 + 27(5/4)
a1 = 423/4 - 27(5/4)
= 423/4 - 135/4
a1 = (423-135)/4
a1 = 288/4
a1 = 72
Thank you.
