Question

Find the 5th term of the sequence -8,-1,6,13

Answer 1

Answer:

so ,here we can clearly see every term is added with number 7

so answer 13+7=20

20+7=27

ur 5th term is 20 and 6th term is 27

Answer 2

$\huge{\underline{\underline{\bf Given}}}$

• $\sf a = -8$
• $\sf d = +7$
• $\sf n = 5$

$\huge{\underline{\underline{\bf To\:find}}}$

• $\sf a_{5} = ?$

$\huge{\underline{\underline{\bf Formula}}}$

$\underline\pink{\boxed{\bf a_{n} = a+(n-1)d}}$

$\huge{\underline{\underline{\bf Solution}}}$

$\implies \sf a_{5} = a + 4d \\ \\ \implies \sf a_{5 }= - 8 + 4(7) \\ \\ \implies\sf a_{5} = - 8 + 28 = 20$

hence our required answer is 20

$\huge{\underline{\underline{\bf Additional \:information}}}$

to find sum of n terms following formula is Used:-

$\underline\green{\boxed{\bf S_{n} = \dfrac{n}{2}×[2a(n-1)d]}}$

OR

$\underline\orange{\boxed{\bf S_{n} = \dfrac{n}{2}×a+d}}$