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.) y = 18(1.15)x

Answer 1

Answer:

$y = 18 * 1.15^x$

Step-by-step explanation:

Given

$a = 18$ --- initial

$r =15\%$ -- rate

Value after a year = $20.70

Required

Expression to calculate its value after y years

This is calculated using:

$y = ab^x$

Where

$b=1 +r$

Substitute $r =15\%$ in $b=1 +r$

$b = 1 + 15\%$

$b = 1 + 0.15$

$b = 1.15$

Substitute $b = 1.15$ and $a = 18$ in $y = ab^x$

$y = 18 * 1.15^x$