Karana's mom bought her two items using a credit card. The first item cost $252, and the second item cost $351. Later, she returned both items to the store. What was the change in the amount owed to the credit card company from returning both items?

Asquare parking lot has 6,400 square meters what is the length in meters

Acircle has a circumference of 28.36 units what is the diameter of the circle

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.