Factorise 15xy-6x+5y-2

The last time i bought this product , it cost $20.00 but it looks like it cost 29. 60 today? what is the increase

1- 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.2- 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 the first question?

Subject: geometryneed with 6 and 7