Question

In an AP the relation between a5 and a7 and common difference is ___ (a) a5 = a7 + 2d (b) a5 = a7 + d (c) a7 = a5 + 3d (d) a7 = a5 +2d

Answer 1

let the first term of A.P be a Nd common difference d

thus

a5 = a+(5-1)d = a+4d -----1

a7 = a+(7-1)d = a+6d ------2

now 2-1

a7 -a5 = a+6d-(a+4d)

a7-a5 = a+6d-a-4d

a7-a5 = 2d

a7 = a5 +2d

thus option d is correct

Answer 2

Answer:

option f is correct

Step-by-step explanation:

let the first term of A.P be a Nd common difference d

thus

a5=a+(5-1)d=a+4d.....1

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

now 2-1

a7 -a5=a+6d-(a+4d)

a7-a5=a+6d-a-4d

a7=a5=2d

a7=a5+2d

the option d is correct