Nick starts with 20 milligrams of a radioactive substance. The amount of the substance decreases by each week for a number of weeks, w. He writes the
expression 20(3)" 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 5091 each week for a number of weeks, w. She writes the
expression (1 – 0.5)" 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.

Data for the height of a model rocket launch in the air over time are shown in the table. darryl predicted that the height of the rocket at 8 seconds would be about 93 meters. did darryl make a good prediction? yes, the data are best modeled by a quadratic function. the value of the function at 8 seconds is about 93 meters. yes, the data are best modeled by a linear function. the first differences are constant, so about 93 meters at 8 seconds is reasonable. no, the data are exponential. a better prediction is 150 meters. no, the data are best modeled by a cubic function. a better prediction is 100 meters.