Question

nth term of sequence is a+nb find a4-a3

Answer 1

4th term - 3rd term =
$(a + 4b) - (a + 3b) = b$

Answer 2

For a4 take a+3d and for a3 take a+2d
Now subtract
a+3d-a+2d Equate this eq.
So, +a and -a cancelled
5d is equal to 0
So, the answer is d=1/5