What are the roots of the equation? x2−x−42=0 Enter your answers in the boxes.

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.

Write as a product of two polynomials. 2(3–b)+5(b–3)^2

Which angle of rotation is an angle of rotational symmetry for all figures?