Arational expression is undefined whenever it’s denominator is zero true or false

Which is the graph of the function y=2(4)^x

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.

At 6 1/2 cents per pound of string beans how much does 7 pounds cost