Show that each of the progressions given below is an AP. Find the first term, common difference and next term of each.

11, 6, 1, - 4, ...

Here, T₂ - T₁ = 6 - 11 = - 5

T₃ - T₂ = 1 - 6 = - 5

T₄ - T₃ = - 4 - 1 = - 5

Since the difference between each consecutive term is same, ∴ the progression is an AP.

So, first term = 11

Common difference = 6 - 11 = - 5

Next term = T₅ = T₄ + d = - 4 + (-5) = - 9