Help please i need them both answered

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?

Write 5 in the form of a/b using integers to show it as a rational number

What rule describes a dilation with a scale factor of 4 and the center of dilation at the origin?