Nick starts with 20 milligrams of a radioactive substance. The amount of the substance decreases by 14 each week for a number of
weeks, w. He writes the expression 20(14)w to find the amount of radioactive substance remaining after w weeks. Autumn starts with 5 milligrams of a radioactive substance. The amount of the substance decreases by 50% each week for a number of weeks, w. She writes the expression (1?0.5)w to find the amount of radioactive substance remaining after w weeks. Use the drop-down menus to explain what each part of Nick's and Autumn's expressions mean.
In Eric's expression,20 represents the initial amount of substance with which he has started the experiment. is the amount of substance left after each time period (in this case, each week).The variable w in this case represents the number of weeks.
Andrea's expression can be written as :
The one outside of parentheses represents the initial amount of the substance. The one inside of parentheses represents 100% of the original amount of the substance. 0.5 represents the 50% of the substance that is lost each time period. The variable w in this case represents the number of weeks.
Nick starts with 20 milligrams of a radioactive substance. The amount of the substance decreases by 12 each week for a number of weeks, w. He writes the expression 20(12)w to find the amount of radioactive substance remaining after w weeks.
Autumn starts with 1 milligram of a radioactive substance. The amount of the substance decreases by 50% each week for a number of weeks, w. She writes the expression (1−0.5)w to find the amount of radioactive substance remaining after w weeks.
Use the drop-down menus to explain what each part of Nick's and Autumn's expressions mean.
