Predicate Logic Help

I need some help with the following two predicate logic problems:
Complete the following predicate logic proof (2 points):

1. x (Px → Rx) Given
2. x (Rx → Sx) Given
3. x (Tx ↔ Sx) Given
4. ~xTx Given.
5. SHOW: ~xPx

Complete the following predicate logic proof.

x (Ax Bx)
~x (Cx Bx)
SHOW: x (Cx & ~Ax)

You can use the predicate-logic version of any propositional logic rule.
Some special predicate logic rules you might want to use:
Quantifier Obversion, Quantifier Instantiation and Generalization.