Question

The nth term of an AP is 7-4n. Find common difference. ​

Answer 1

a1 = 7-4(1) = 7-4 = 3

a2 = 7-4(2) = -1

thus, d=-1-3 = -4

Answer 2

Answer:

let n=1

then,

a(1) = 7-4(1)

= 7-4 = 3 = a1

let n=2

then,

a(2) = 7-4(2)

= 7-8 = -1 = a2

let n =3

then,

a(3) = 7-4(3)

= 7-12 = -5 = a3

now

AP = 3, -1,-5

D = a2- a1

= -1-3 = -4

therefore,

d= -4