Question

(
10th term of 9, 5, 1, -3, ...​

Answer 1

Answer:

$\large{\underline{\boxed{\sf a_{10}=-27}}}$

Step-by-step explanation:

Given that ;

• a = 9
• d = (5 - 9) = - 4
• n = 10

Now, we know that -

$\implies \bf a_n = a + (n - 1)d \\ \\ \implies \bf a_{10} = 9 + (10 - 1)( - 4) \\ \\ \implies \bf a_{10} =9 + 9( - 4) \\ \\ \implies \bf a_{10} =9 - 36 \\ \\ \implies \bf a_{10} = - 27$

Hence, the 10th term is (-27).

$\rule{300}{2}$

Arithmetic Progression : A list of numbers in which every term is obtained by adding of subtracting a fixed number to the next term except the first term, is called Arithmetic Progression (AP).

The general form of A.P is -

a, (a + d), (a + 2d), (a + 3d)..... (a + nd).

Answer 2

Answer:

$\huge{\red{\boxed{\boxed{\green{\sf{a10=-27}}}}}}$

Step-by-step explanation:

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

□a1=9

□a2=5

□Common difference=a2-a1=5-9=-4

To find:

○a10=?

${ \boxed { \red{detail \: method}}} \\ a = 9 \\ d = - 4 \\ n = 10\\ \\ a10 = a + (n - 1)d \\ a10 = 9 + (10 - 1) \times - 4 \\ a10 = 9 + ( - 36) \\ a10 = - 27 \\ \\ { \boxed{ \green {short cut \: method}}} \\ a10 = a + 9d \\ a10 = 9 + 9 \times - 4 \\ a10 = 9 - 36 \\ a10 = - 27$

$\huge{\red{\boxed{\boxed{\green{\sf{a10=-27}}}}}}$

_________________________________________