Sup kids I need help and you guys are way smarter than me

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.

To convert celsius temperatures to fahrenheit, you can use the expression (c + 32). tom says that another way to write this expression is c + 32. what error did tom make?

What is the scale factor of axyz to auvw?