A gardener wants to fence three sides of the yard in front of her house. She bought 60 m of fence and wants an area of about 400m^2. The
quadratic equation f(x) = 60x - 2x^2, where x is the width of the
yard in metres and f(x) is the area in square metres, gives the area
that can be enclosed. Determine the dimensions that will give the
desired area.

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.