Question

write common difference of a Arithmetic progression whose Nth term is 7-5n

Answer 1

Given,

Nth term=7-5n

A nth = 7-5n

Put n=1

A1=7-5

A1=2

Now again put n=2

A2=7-5×2

A2=-3

So common difference =A2-A1

C.d=-3-2

So common difference is -5

Answer 2

Answer:

Step-by-step explanation:

We had given that

T =7-5n

Let n=1

:. T1 = 7-5(1)

= 7-5 = 2

:. T1=2

Let n=2

:.T2 = 7-5(2)

= 7-10 = -3

:.T2= -3

Let n =3

:.T3 = 7-5(3)

= 7-15 = -8

:.T3 =-8

Now,.

T2-T1 = -3-2

= -5

T3-T2 = -8+3

= -5

Since,. T3-T2= T2-T1

:. It is in A.P.

:. Common difference = d = -5