Question

The 10th term of an AP exeeds 30 than its 4th term. Then find the d .
If its 21st term is 108 find its 1st term and
Write its algebraic form

Answer 1

Answer:

d= 5/2

a= 58

Step-by-step explanation:

a10-a4=30

a+9d-a+3d=30

12d=30

d=5/2

a21=108

$an = a + {n - 1}d$

108=a+(21-1)(5/2)

108=a+(20)(5/2)

108=a+50

108-50=a

58=a