Eric starts with 10 milligrams of a radioactive substance, The amount of the substance decreases by z each week for a number of weeks, W. He writes the expression
10(%)" to find the amount of radioactive substance remaining after w weeks.
Andrea starts with milligram of a radioactive substance. The amount of the substance
decreases by 20% each week for a number of weeks, w. She writes the expression
(1 0.2)" to find the amount of radioactive substance remaining after w weeks.
Use the drop-down menus to explain what each part of Eric's and Andrea's
expressions mean.