13. Town officials are putting a pathway around a pool as shown below. (4x+3)
pool
(2x-5) ft
deck
a) Determine the perimeter of the pool in terms of x. Write your answer in simple form and
include units. Show or explain your work.
b) Determine the area of the pool in terms of x. Write your answers as a trinomial and include
units. Show or explain your work.

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.