Question

The first term of an A.P. is – 3 and the 10th tam is 15. ​

Answer 1

▬▬▬▬▬ஜ۩۞۩ஜ▬▬▬▬▬▬

$\mathfrak{The\:Answer\:is}$ ⭐

$a = - 3 \\ \\ a10 = a + 9d \\ \\ 15 = - 3 + 9d \\ \\ 18 = 9d \\ \\ 2 = d$

$\boxed{Hope\:This\:Helps}$

HopeThisHelps

▬▬▬▬▬ஜ۩۞۩ஜ▬▬▬▬▬▬

Answer 2

♣ Given :

• First term (a) = -3
• 10 th term (a10) = 15

♣ To Find

Common difference and first 3 terms

♣ Solution

We are given that the 10 th term of an A.P is 15 and first term is -3. So, by putting these values in formula we can get common difference.

♠ Formula for 10 th term :

a10 = a + 9d

⇒15 = -3 + 9d

⇒15 + 3 = 9d

⇒18 = 9d

⇒d = 18/9

⇒d = 2

•°• So, common difference (d) is 2

----------------------------------------------------

Now Similarly for First 3 terms :

♠ a1 = a

⇒a1 = -3

_______________________

♠ a2 = a + 2

⇒a2 = -3 + 2

⇒a2 = -1

_______________________

♠ a3 = a + 2d

⇒a3 = -3 + 2(2)

⇒a3 = -3 + 4

⇒a3 = 1

So, A.P is -3,-1,1...........