What is 7x2 – 4 + 6x3 – 4x – x4 in standard form? A.–4 – 4x + 7x2 + 6x3 – x4

B.4(–4 – x) + x2(7 + 6x – x2)

C. x4 + 6x3 + 7x2 – 4x – 4

D.–x4 + 6x3 + 7x2 – 4x – 4

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?