Question

find the value of T15 for AP 4,9,12......​

Answer 1

Answer:

We have,

a= First term =4

d= Common difference =5

We know that the n

th

term of an A.P. with first term a and common difference d is given by

t

n

=a+(n−1)d

t

15

=a+(15−1)d

=4+(14)5

=4+70

t

15

=74

Mark me branilst

Answer 2

Answer:

an = a+(n-1)*d

n=15

a=4

d = a2-a1 =5

a15= 4+(15-1)*5

= 4+(14)*5

=4+70

=74

:. t15= 74