Adding mixed numbers. could someone explain this to me ? find the sum or difference 5/6 + 4/9 a. 1 1/2 b. 1 5/18 c. 9/18 d. 1/2

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?