Grace gives her sister a riddle: i have number x. i add 15 to twice x to get result a. i subtract 4 from x to get result b. i multiply result b by 3 to get result c. result a is equal to result c. grace's sister said the riddle cannot be solved, but grace thought otherwise. who is right? explain

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?