Question

what is the nth term of 15,12,9,6

Answer 1

Answer:

$\huge{\pink{\green{\sf{a_{n}=18-3n}}}}$

Step-by-step explanation:

$\huge{\pink{\green{\underline{\red{\sf{SOLUTION-}}}}}}$

▪At first check whether the given series is in the form of A.P or not.

▪So a2-a1=a3-a2

》12 - 15 = 9 - 12

》 -3 = -3

▪Given sequence is in A.P.

• According to given question:

▪We have to find the nth term of this series.

▪Formula for nth term of series

${ \green{ \to a_{n} = a + (n - 1)d}}$

▪Putting given values in this formula

$\to a_{n} = 15 + (n - 1) \times ( - 3 )\\ \to a_{n} = 15 + ( - 3n + 3) \\ \to a_{n} = 15 - 3n + 3\\ { \green{\therefore a_{n} = 18 - 3n}}$

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