Question

find the 11th term from the last term of ap 27,23,19,....-65

Answer 1

Hi ,

27 , 23 , 19 ,...., - 65 is an A.P

a = 27 ,

common difference = a2 - a1

d = 23 - 27 = - 4

Rewrite the A..P ,

- 65 , - 61 , - 57 , ... 19 , 23 , 27

here ,

first term = a = - 65

common difference = a2 - a1

d = - 61 - ( - 65 )

d = -61 + 65

d = 4

n = 11

nth term = an = a + ( n - 1 )d

a11 = -65 + ( 11 - 1 ) 4

= -65 + ( 10 × 4 )

= -65 + 40

= -25

Therefore ,

required 11th term = a11 = - 25

I hope this helps you.

:)

Answer 2

27, 23, 19, .................., – 65

d = $\bf\huge a_{2}$ –  $\bf\huge a_{1}$

=> 23 – 27 = – 4

will take d = 4 and  $\bf\huge a_{1}$  = – 65

$\bf\huge a_{11}$ =  $\bf\huge a_{1}$ + (11 – 1)d

= – 65 + 10(4)

= – 65 + 40

= – 25