I am stuck on 3 proofs for my discrete math class. Any help would be greatly appreciated.

Prove that if R is a partial order, then ${R}^{-1}$ is a partial order

Prove that if ${R}_{1}$ and ${R}_{2}$ are equivalence relations on the set A, then ${R}_{1}\cap {R}_{2}$ is an equivalence relation.

Prove that if R is a partial order, then ${R}^{-1}$ is a partial order

Prove that if ${R}_{1}$ and ${R}_{2}$ are equivalence relations on the set A, then ${R}_{1}\cap {R}_{2}$ is an equivalence relation.