Please help due today!

Convert the cartesian equation (x 2 + y 2)2 = 4(x 2 - y 2) to a polar equation. choices: r4 = -4r2 r2 = 4cos2θ r2 = 4sin2θ

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?

Aye asap pls ! markin da brainiest too ! btw da step choices are all add, distribute, divide, n subtract