Give the form of each argument. Then prove whether the argument is valid or invalid. For valid arguments, use the rules of inference to prove validity.

(a)

If I get a job then I will buy a new car and a new house. I won't buy a new house. I will not get a job.

(b)

If I get a job then I will buy a new car or a new house (or both).

I won't buy a new house. I will not get a new job.