Question

the 8th term of an AP is -23 and 12th term is 39 find the AP

Answer 1

Solve.....
Your question...

Answer 2

*:..｡o○☆ HEYA MATE !☆○o｡..:*

GIVEN :

The 8th term of an AP is - 23 .

The 12th term of an AP is 39.

TO FIND :

The AP

ANSWER :

The general term,tn =

$tn = a + (n - 1)d$

where n is the nth term.

a is the first term.

d is the common difference.

t8 = a + ( 8 - 1) d

a + 7d = -23 ________(1)

t12 = a + (12 - 1) d

a + 11d = 39 _________(2)

Subtract (1) & (2) ,

(2) => a + 11d = 39

(1) => a + 7d = -23

(-) (-) (+)

_________________

4d = 16

d = 16/4

d = 4

Substitute the value of d = 4 in equation (1),,,,

(1) => a + 7 (4) = -23

a + 28= -23

a = -28 - 23

a = -51

The general form of an AP is ,,,,,

$ap \: = (a) , (a + d) , (a + 2d) , ..$

AP = 51, ( 51 +4) , ( 51 + 2 × 4 ) ,....

AP = 5 1, 55 ,59 , ...

∝╬══→HOPE U LIKE IT