Question

The 15 th term of the AP: –23,–19,–15 is

Answer 1

Answer:

$\bigstar{\bold{Fifteenth\:term(a_{15})\:=33}}$

Step-by-step explanation:

$\Large{\underline{\underline{\bf{Given:}}}}$

• A.P is -23, -19, -15.......

$\Large{\underline{\underline{\bf{To\:Find:}}}}$

• 15th term of the A.P (a₁₅)

$\Large{\underline{\underline{\bf{Solution:}}}}$

→ The common difference(d) of an AP is given by

  d = a₂ - a₁

Here a₂ = -19, a₁ = -23

→ Substituting the datas we get,

d = -19 + 23 = 4

→ The 15th term of an AP is given by the formula

$a_{15}=a_1+(15-1)d$

→ Substituting the datas we get,

$a_{15}=-23+14\times 4$

$a_{15}=-23+56$

$\boxed{\bold{Fifteenth\:term(a_{15})=33}}$

$\Large{\underline{\underline{\bf{Notes:}}}}$

→ nth term of an AP is given by the formula

$a_n=a_1+(n-1)d$

→ The common difference of a AP is given by

• $d=\dfrac{a_m-a_n}{m-n}$

• $d=a_2-a_1$