Y’all help me please?

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.

Which question is not a good survey question? a. don't you agree that the financial crisis is essentially over? 63on average, how many hours do you sleep per day? c. what is your opinion of educational funding this year? d. are you happy with the availability of electronic products in your state?

Solve the formula ax+ by = c for x.