Question

In an AP fourth term is -13/2, 17th term is zero
and last one is 21. Find the first term.​

Answer 1

Step-by-step explanation:

Given:

a4= a+3d

=-13/2

a17=a+16d

=0

l=21

Now, subtract these

a+16d=0

a+3d=-13/2

13d=13

d=1/2

put d=1/2 in a+3d,we get

a+3(1/2)=-13/2

a=-8

Hence,first term is -8