Question

Find the 25th term of an A.P. whose 9th term -6 and common difference
5/4 is.
Please give answer fastly....​

Answer 1

Answer:

a9 = -6 d = 5/4

a + 8d = -6

a + 8(5/4) = -6

a + 40/4 = -6

a + 10 = -6

a = -6 - 10

a = -16

a25 = a + 24 d

= -16 + 24 (5/4)

= -16 + 120/4

= -16 + 30

a25 = 14

Thank you

Answer 2

Given,

9th term of an A.P is ($a_{9}$)=-6 and common difference (d) = $\frac{5}{4}$

To Find,

25th term of A.P $a_{25}$ .

Solution,

$a_{9} = a+ 8d =-6\\ \\a + 8(\frac{5}{4})=-6\\ \\a+ \frac{40}{4} =-6\\ \\a+10 = -6\\a=-6-10\\a= -16$                     (1)

now,

$a_{25}=a+24d\\ \\=-16 + 24(\frac{5}{4})$

= -16 +$\frac{120}{4}$

= -16 +30

= 14

Hence the 25th term of the A.P is 14.