Question

fill in the blanks in given picture .

it is given that a is first term
d is common difference

and an is nth term of AP


BEST OF LUCK !!!!!!!!

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Answer 1

$\huge \bf \red{ \mid{ \overline{ \underline{ANSWER}}} \mid}$

$\bf {\pink{step \: by \: step \: explanation}}$

(i) Given-

a1 = 7

d = 3

n = 8 .

To find -

an =?

» an = a1 + ( n - 1 )d .

→ 7 + ( 8 - 1 ) 3 .

→ 7 + 21 .

→ 28 .

(ii) Given-

a1 = -18

n = 10

an = 0.

To find -

d=?

» an = a1 + ( n - 1 )d .

→ 0 = -18 + ( 10 - 1 ) d .

→ 18 = 9d.

→ d = 18/9 .

d = 2 .

(iii) Given -

an = -5

d = -3

n = 18 .

To find =

a1 =?

» an = a1 + ( n - 1 )d

→ -5 = a + ( 18 - 1 ) -3 .

→ -5 = a - 51 .

→ a = 51 - 5 .

a1 = 46 .

(iv) Given-

→ a1 = -18.9

→ d = 2.5

→ an = 3.6 .

To find -

n=?

» an = a1 + ( n - 1 )d .

→ 3.6 = -18.9 + ( n - 1 ) 2.5 .

→ 3.6 + 18.9 = 2.5n - 2.5 .

→ 22.5 + 2.5 = 2.5n .

→ n = 25/2.5

→ n = 10 .

(v) Given -

› a1 = 3.5

› d = 0

→ n = 105 .

To find -

an =?

» an =a1 + ( n - 1 )d .

→ 3.5 + ( 105 - 1 ) 0 .

→ 3.5 + 0 .

→ 3.5 .

Answer 2

$\huge \bf \red{ \mid{ \overline{ \underline{ANSWER}}} \mid}$

$\bf {\pink{step \: by \: step \: explanation}}$

(i) Given-

a1 = 7

d = 3

n = 8 .

To find -

an =?

» an = a1 + ( n - 1 )d .

→ 7 + ( 8 - 1 ) 3 .

→ 7 + 21 .

→ 28 .

(ii) Given-

a1 = -18

n = 10

an = 0.

To find -

d=?

» an = a1 + ( n - 1 )d .

→ 0 = -18 + ( 10 - 1 ) d .

→ 18 = 9d.

→ d = 18/9 .

d = 2 .

(iii) Given -

an = -5

d = -3

n = 18 .

To find =

a1 =?

» an = a1 + ( n - 1 )d

→ -5 = a + ( 18 - 1 ) -3 .

→ -5 = a - 51 .

→ a = 51 - 5 .

a1 = 46 .

(iv) Given-

→ a1 = -18.9

→ d = 2.5

→ an = 3.6 .

To find -

n=?

» an = a1 + ( n - 1 )d .

→ 3.6 = -18.9 + ( n - 1 ) 2.5 .

→ 3.6 + 18.9 = 2.5n - 2.5 .

→ 22.5 + 2.5 = 2.5n .

→ n = 25/2.5

→ n = 10 .

(v) Given -

› a1 = 3.5

› d = 0

→ n = 105 .

To find -

an =?

» an =a1 + ( n - 1 )d .

→ 3.5 + ( 105 - 1 ) 0 .

→ 3.5 + 0 .

→ 3.5 .