Question

Find an explicit rule for the nth term of the sequence.

-3, -15, -75, -375, ...

Answer 1

I got an = -3 • 5n - 1

Answer 2

the problem (assuming that -3 is referred to as n= 0) is that you don't get the first term in the sequence.

one thing to try here it to use some number to a power (because any number to the 0th power is one)

Answer 3

Continue...wait, is my answer incorrect?

Answer 4

it is incorrect, for n = 0, you got -3( 5 * 0) - 1
0 - 1

if you put in n = 1, you get -3 (5 * 1) -1
-15 - 1

Answer 5

oh wait, I misread the sequence. you go tit right

Answer 6

it is a G.P with C.R=-15/-3=5
tn =ar^(n-1)

Answer 7

a is first term, r is a C.R

Answer 8

tn=-3(5)^(n-1)

Answer 9

Thank You, @alexandercpark and @surjithayer :)