Question

Find the 15th term of the geometric sequence 2,−8,32,...

Answer 1

Answer: first term (a)= 2

second term (b) = -8

common ratio (r) = -8/2 = -4

15th term = ar^ (n-1)

               = 2* (-4)^ 14 =536870912

Step-by-step explanation:

Answer 2

Answer:

536,870,912

Step-by-step explanation:

the formula for geometric sequences is:

aₙ = a₁·$r^{n-1}$

where aₙ is, in this case the 15th term

r = common ratio which, in this case, is -4

a₁ = first value in the sequence

so:

a₁₅= 2(-4)^14

= 2(268,435,456)

= 536,870,912