Find the perimeter and area of the polygon

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

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?

In september, louise planted a tree. every month, the tree louise planted grew 2 inches. what would the constant of proportionality of the line be?