Question

find the AP whose third term is 5th and 7th term is 9​

Answer 1

Step-by-step explanation:

t3 = 5

a +2d = 5.......(1)

t7 = 9

a +6d = 9.......(2)

from (1)&(2)

4d = 4

d = 1

a+2d = 5.....(from (1))

a +2 = 5

a = 3

so your required A.P is=>

3,4,5,6,7....

Answer 2

Answer:

a3 = a + (3 – 1)d = a + 2d = 5 ... (1)

a7 = a + (7 – 1)d = a + 6d = 9 ... (2)

Solving the pair of linear equations (1) and (2),

a = 3, d = 1

Hence, the required AP is 3, 4, 5, 6, 7, ...