Nadya's cell phone provider charges a monthly fee of $35 for usage up to 200 minutes. If she uses more than this in a month, she is charged $0.23 for each additional minute. Let c represent the cost of Nadya's bill if she uses m minutes of air time. Write an expression that can be used to find c if she used more than 200 minutes last month.

1- is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis. 2- 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. 3- 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 part b?