Question

A limited edition poster increases in value each year with an initial value of $18. After 1 year and an increase of 15% per
year, the poster is worth $20.70. Which equation can be used to find the value, y, after x years? (Round money values to
the nearest penny)

Answer 1

Answer:

$y=18(1.15)^x$

Step-by-step explanation:

we know that

The equation of a exponential growth function is equal to

$y=a(1+r)^x$

where

y ---> the value of the poster

x ---> the number of years

r ---> is the growth rate of change

a ---> is the initial value

In this problem we have

$a=18\\r=15\%=15/100=0.15$

substitute

$y=18(1+0.15)^x$

therefore

$y=18(1.15)^x$

Examples

For x=5 years

$y=18(1.15)^5=\ 36.20$

For x=8 years

$y=18(1.15)^8=\ 55.06$

For x=10 years

$y=18(1.15)^{10} =\ 72.82$

Answer 2

Answer:

Option A

Step-by-step explanation:

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