A piece of luggage sells for $225.00. It is on sale this week for $195.00. What is the percent decrease, to the nearest whole percent?

Aline on the wall and a line on the floor are skew. always, sometimes, or never?

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

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.