19. A gym charges a membership fee plus an additional fee per yoga class. The table shows the linear relationship between the number of yoga classes taken and the total cost including the membership fee. Yoga Classes Number of Yoga Classes 6 Total Cost 8. 10 14 20 $67.50 $75.00 $82.50 $97.50 $120.00 Which statement is true? A. The additional fee per yoga class is $3.75. B. The additional fee per yoga class is $8.25. C. The membership fee is $35.00. D. The membership fee is $42.50.

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.