Consider the three transactions T₁, T₂, and T₃, and the schedules S₁ and S₂ given below. Draw the serializability (precedence) graphs for S₁ and S₂, and state whether each schedule is serializable or not. If a schedule is serializable, write down the equivalent serial schedule(s).

T₁: r₁ (X); r₁ (Z); w₁ (X);
T₂: r₂ (Z); r₂ (Y); w₂ (Z); w₂ (Y);
T₃: r₃ (X); r₃ (Y); w₃ (Y);
S₁: r₁ (X); r₂ (Z); r₁ (Z); r₃ (X); r₃ (Y); w₁ (X); w₃ (Y); r₂ (Y); w₂ (Z); w₂ (Y);
S₂: r₁ (X); r₂ (Z); r₃ (X); r₁ (Z); r₂ (Y); r₃ (Y); w₁ (X); w₂ (Z); w₃ (Y); w₂ (Y);