The state sales tax in north carolina is 4.5%. Estimate the states sales tax on a model of the wright brothers' airplane that costs $139.99

Which unit of measure would be the most appropriate to measure the capacity of a bottle of nail polish? a.fluid ounces b.cups c.pints d.quarts e.gallons

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?

Pls brainliest will be awarded if answer is correct