CUNY All Prime Numbers Greater than Two Are Odd Argument Valid or Invalid Discussion

4) Is the following argument valid or invalid? Justify your answer.

All prime numbers greater than 2 are odd.

The number ?? is not prime.

Therefore, the number ?? is not odd.

5) Prove or disprove the following statement. Do not use any other facts previously proved in class or

in your text or anywhere else.

For all integers ??, ??, and ??, if ?? | ?? and ?? | ??, then ?? | (5?? + 3??).

7) For all real numbers ?? and ??, if ?? is rational and ?? is irrational, then ?? + 2?? is irrational.

(Be sure to indicate whether you are using the method of proof by contradiction)

solve and follow the drecti