Simplify. Write the expression using only positive exponents.
5b^-2/b^-3

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*

Calculate the missing value. round the answer to on decimal place. start with 70, increase it by 21%, and end up with

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.