the cost of a parking permit consists of a one - time administration fee plus a monthly fee. a permit…

the cost of a parking permit consists of a one - time administration fee plus a monthly fee. a permit purchased for 12 months costs $660. a permit purchased for 15 months costs $810. what is the administration fee?\n$50\n$54\n$55\n$60

the cost of a parking permit consists of a one - time administration fee plus a monthly fee. a permit purchased for 12 months costs $660. a permit purchased for 15 months costs $810. what is the administration fee?\n$50\n$54\n$55\n$60

Answer

Answer:

D. $60

Explanation:

Step1: Definir variables

Sea $x$ la tarifa mensual y $y$ la tarifa administrativa. Tenemos las ecuaciones: $12x + y=660$ y $15x + y = 810$.

Step2: Restar ecuaciones

$(15x + y)-(12x + y)=810 - 660$. $15x + y-12x - y=150$. $3x=150$, entonces $x = 50$.

Step3: Encontrar $y$

Sustituir $x = 50$ en $12x + y=660$. $12\times50+y=660$. $600 + y=660$. $y=660 - 600=60$.