Mt. mckinley, which is the highest elevation in north america, is 20,320 feet above sea level. death valley, which is the lowest elevation in north america, is 282 feet below sea level. what is the difference in height between the top of mt. mckinley and the bottom of death valley?

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?