Write the following set in set-builder (Rule Method) form :

B₁ = {6, 9, 12, 15, …………… }

B₁ = {6, 9, 12, 15, …………… }

B₁ = {3 x 1 + 3, 3 x 2 + 3, 3 x 3 + 3, 3 x 4 + 3,……………}

B₁ = {x : x = 3n + 3, n ∈ N}