Element X decays radioactively with a half life of 9 minutes. If there are 960 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to decay to 40 grams?

Which of the following represents a number squared is equal to twenty more than nine times that number ? a) x squared = 9x + 20 b) x squared = 20x + 9 c) x squared > 9 + 20x d) x squared = 9 + x + 20

The art class is planning to paint a mural on an outside wall. this figure is a scale drawing of the wall. width: 11 in length: 28 in unit rate: 1.5 ft per in. write the ratio of the area of the drawing to the area of the actual mural. write your answer as a unit rate. show that this unit rate is equal to the square of the unit rate 1.5 ft per in

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0