13.El alquiler de un coche cuesta 20 € al día, más 0'50 € por kilómetro recorrido. Halla la ecuación que calcula lo que se cobra diariamente por el alquiler del coche en función de los kilómetros recorridos. Representa la función obtenida.

The perimeter of a rectangle is greater than or equal to 74 meters. if the length is 25 meters, the minimum width of the rectangle is meters.

Satchi found a used bookstore that sells pre-owned dvds and cds. dvds cost $9 each, and cds cost $7 each. satchi can spend no more than $45.

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?