Question

Find a4 when a₁ = 3 and r = -2
Select one:
a. - 24
b. 16
c. 24
d.- 16

Answer 1

To find the fourth term (a4) of a geometric sequence with a₁ = 3 and a common ratio (r) of -2, we can use the formula:

aₙ = a₁ * r^(n-1)

where n is the term number.

Let's plug in the values:
a₄ = 3 * (-2)^(4-1)
a₄ = 3 * (-2)^3
a₄ = 3 * (-8)
a₄ = -24

So, the correct answer is:
a. -24

Answer 2

This is a geometric series with first term 3 and common ratio -2.

Second term: 3 × -2 = -6

Third term: -6 × -2 = 12

Fourth term: 12 × -2 = -24

The correct answer is A.