Orlando bought a new couch for $2,904, using the furniture store's finance plan. he will pay $121 a month for 24 months. which equation can orlando use to find out how much money he still owes after each month of the plan?
a. y= 2,904 121x
b. y= 2,904 - 121x
c. y= 121x - 2,904
d. y= 121x

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.