A limited edition poster increases in value each year with an initial value of $18. After one year and an increase of 15% per year, the poster is worth $20.70. Which equation can be used to fund the value, y, after x years?

We have been given that a limited edition poster increases in value each year with an initial value of $18. After one year and an increase of 15% per year, the poster is worth $20.70.  

We will use exponential growth formula to find our required equation.

We know that an exponential function is in form , where

a = Initial value,

r = Growth rate in decimal form,    

x = Time.    

Let us convert 15% into percentage.

Initial value is 18.

Upon substituting these values in above formula, we will get:

Let us check our function by finding the value of poster after one year as:

Since the value of poster after 1 year matched with our findings, therefore, the equation can be used to fund the value, y, after x years.

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