True or False?

Question

 

The sequence is geometric and the common ratio is -5.

1, -5, 25, -125, 625, ...

Answer 1

Alexis,

First of all, by definition a geometric ratio must follow a pattern by multiplying by a single value from one term to the next. To answer this as true or false, experiment with the common ratio. Multiply by the common ratio of -5 each given value to see if it yields the next given value:

 

1 x (-5) = -5 ... true

-5 x (-5) = 25 ... true

...

 

If all the rest prove to be true when multiplied by the given common ratio, then you know it is a geometric sequence and the ratio is, in fact, -5.

 

Hope this helps!