Question

the 7term of an ap is 4 times it is secound term and the 12fth term is 2 more than three times of its fourth term find the prograsion​

Answer 1

Answer :

According to the question,

a+6d=4(a+d).................... (i)

and

a+11d=2+3(a+3d)................. (ii)

solving (i) ;a+6d=4a+4d

2d=3a

a=2d/3........ (iii)

Solving (ii); a+11d=2+3a+9d

2d=2a+2

d=a+1................(iv)

Putting value of d in equation (iii)

a=2(a+1)/3

3a=2a+2

a=2

Putting the value of a in equation (iv)

d=2+1=3

d=3

So the AP is 2,5,8.....