Question

What is the 10th term of the A. P:21, 18,15,12,-------

Answer 1

┍━━━━━━━★━━━━━━━┑

      $\huge\underline{\underline{{\bf\bigstar ANSWER \bigstar}}}$

┕━━━━━━━★━━━━━━━┙

Arithmetic Sequence = 21 , 18 , 15 , 12 , .................

First term = 21

Second term = 18

→ Common Difference = 18 -21

                                    = -3

_________________________________________

       $\boxed{\bf x_{n} = a+( n-1)d}$

→  $\sf x_{10} = 21+(10-1)-3$

→  $\sf x_{10} = 21 + 9 \times -3$

→  $\sf x_{10} = 21-27$

→  $\bf x_{10}=-6$

_________________________________________

HOPE IT HELPS U .... :)