Question

Q 9. If nth term of an AP is (7 – 4n),
then its 23th term is
(a) 99
O (b)-85
(C) 85
O (d) -99​

Answer 1

Answer:

99

Step-by-step explanation:

i hope it help for you .

Answer 2

Answer:

- 85

Step-by-step explanation:

Given,

nth term of an A.P = 7 - 4n

To Find :-

23rd time of an A.P

Formula Required :-

$nth\:term\:of\:an\:A.P(a_n)=a+(n-1)d$

• a = first time
• d = common difference

Solution :-

$7-4n=a+(n-1)d$

Putting 'n' = 1 :-

7 - 4(1) = a + (1 - 1)d

7 - 4 = a

a = 3

First term = a = 3

Putting 'n' = 2 :-

7 - 4(2) = 3 + (2 - 1) d

7 - 8 = 3 + d

-1 - 3 = d

-4 = d

Common difference = d = - 4

23rd term of an A.P :-

$a_{23}=3+(23-1)-4$

= 3 + 22(-4)

= 3 - 88

= - 85

23rd term of an A.P = - 85.

∴ option b