Agroup of students is arranging squares into layers to create a project. the first layer has 4 squares. the second layer has 8 squares. which formula represents an arithmetic explicit formula to determine the number of squares in each layer?
a1 = 4; an = 4 ⋅ an − 1, n > 0
a1 = 4; an = 4 ⋅ an + 1, n > 0
a1 = 4; an = 4 + an + 1, n > 0
a1 = 4; an = 4 + an − 1, n > 0

Antonia and carla have an equivalant percentage of green marbles in their bags of marbles. antonia has 4 green marbles and 16 total matbles. if carla has 10 green marbles , how many total marbles does carla have

40 describe the outliers from the scatter plot.

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.