Which of these expressions are correct variations of the combined gas law?

both

Both: T1 = T2 (P1V1/P2V2)

         V2 = V1(T2/T1)(P1/P2)

To answer this question, we are going to take the expressions in question as;

i) T1 = T2 (P1V1/P2V2)

ii) V2 = V1(T2/T1)(P1/P2)

We are required to determine whether the expressions are correct variation of the Combined Gas Law.

Hence;

P₁V₁/T₁=P₂V₂/T₂

From the equation, we can rearrange it to get the expressions;

T1 = T2 (P1V1/P2V2)

V2 = V1(T2/T1)(P1/P2)

Thus, both expressions are correct variations of the combined gas law.