If the fourth term in a geometric sequence is –1 and the common ratio is –1, find the explicit formula of the sequence. A)

an = (1) ⋅ (–1)n – 1 for n ≥ 1

B)

an = (– 1) ⋅ (1)n – 1 for n ≥ 1

C)

an = (–1) ⋅ (–1)n – 1 for n < 1

D)

an = (1) ⋅ (1)n – 1 for n ≥ 2

What is the probability of drawing three queens from a standard deck of cards, given that the first card drawn was a queen? assume that the cards are not replaced.

What is the reflection image of (5,-3) across the line y = -x?

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.