Q1. How do I know what a expression is called for example 6x^3-9x+3?

Answer 1

it is a polynomial because it is a sum of terms which are coefficients times x^n where n can be any old whole numbers
Since the highest n in this expression is three it is called a cubic polynomial

Answer 2

Thanks-got it cubic trinomial. Here's another one when I have to change signs of negatives and positives for addition and subtraction. How do I do for example 5w^2-4w-7-8w^2+3w-3?

Answer 3

If you just want the name that is a quadratic polynomial because the highest power of w is 2.
your alternating signs make no difference at all. Like 5 w^2 - 8 w^2 = -3w^2

Answer 4

No I do not want the Name I want to know how to figure it out once the numbers are all lined up and it is very confusing when signs need to be switched. Can you please explain that?

Answer 5

5 w^2 - 8 w^2 = -3 w^2

-4 w + 3 w = -1 w

-3 = -3

so
-3 w^2 - 1 w - 3
or
- (w^2 + w +3)

Answer 6

Thanks. There was ( ) on the 8 and the rest because your answer is not one of the answers