Grace starts with 100 milligrams of a radioactive substance. The amount of the
substance decreases by each week for a number of weeks, w. She writes the
expression 100(-)w to find the amount of radioactive substance remaining after w
weeks.
Ryan starts with 1 milligram of a radioactive substance. The amount of the substance
decreases by 40% each week for a number of weeks, w. He writes the expression (1 -
0.4)" to find the amount of radioactive substance remaining after w weeks.
Use the drop-down menus to explain what each part of Grace's and Ryan's
expressions mean.