Given these values for the boolean variables x, y, and z:
x=true; y=true; z=false;
indicate whether each expression is true (t) or false (f):
1) ! (y || z) || x
2) z & & x & & y
3) ! y || (z || x)
4) x || x & & z

1. True.

2. False.

3. True.

4. True.

Explanation:

Remember OR operator (||) gives false when both of it's operands are false. AND Operator (&&) gives false when even one of it's operator is false.

In first part we have  

!(True || False) || True

=!True||True

=False||True

=True

In second part we have.

False && True && True

= False && True

=False.

In Third part

! True || (False || True)

=False || True

=True.

In fourth part

True || True && False

=True|| False

=True.

answer; ///(true) the above statement is

hope it