Tavon has a gift card for $95 that loses $4 for each​ 30-day period it is not used. He has another gift card for $85 that loses $3.50 for each​ 30-day period it is not used.
a. Write and solve an equation for the number of​ 30-day periods until the value of the gift cards will be equal.
b. What will the value of each card be when they have equal​ value?

Respuesta :

Answer:

20 periods, $15

Step-by-step explanation:

We can set up 2 equations for each card.

The first is 95-4x

x represents each 30 day period.

The second equation is 85-3.5x

95-4x=85-3.5x

95=85+.5x

10=.5x

x=20

It will take 20 periods til they equal each other.

We plug in 20 for x to find the value.

95-4(20)=15

They will be at $15