Assuming the sequence goes on like this 11,-33,99,-297,891,...,
its general formula is

So, the 9th term is
Answer:
The leverage of an observation is determined by how far the values of the independent variables are from their means.
Answer:
No
Step-by-step explanation:
it's not always possible to factor a quadratic expression of this factoring by grouping. The method doesn't work when an expression cannot be factored as (Ax+B)(Cx+D) where A, B, C and D are integrers.
In that case, you should use other methods.