Answer
a) There is a system in open state
b) All systems are either in malfunctioning state or diagnostic state
c) There is a system in open state or diagnostic state
d) There is a system which is not in available state
e) All systems are not in working state
Work Step by Step
First decide if the statement is true for all range denoted by $\forall$ or it's true for a single range denoted by $\exists$. Then put S(x,y) in terms “x is in state y”. If there's a negation sign $\neg$ before S(x,y) it means "x is not in y".