## Brooke2013 3 years ago Zach wrote the formula w(w-1)(5w + 4) for the volume of a rectangular prism he is designing, with width w, which is always has a positive value greater than 1. Find the product and then classify this polynomial by degree and by number of terms. Choices:) A.) 5w^5 - w^4 - 4w^3; quintic trinomial B.) 20w^2; quadratic monomial C.) 5w^3 - w^2 - 4w; cubic trinomial D.) 5w^4 - w^3 - 4w^2; quartic trinomial

1. malical

Well, first I would factor the (w-1)(5w+4) and the multiple the result by the remaining w. See which answer choice you get.

2. Brooke2013

When you factor (w-1)(5w+4) without multiplying the remaining with the w do you get 5w^2 - 4w + 5w + 4

3. malical

Not quite. The first and last terms are correct but you need to: (-1)(5w) and (4)(w) In other words, look at you signs. Also, you should add those two together because they share a common variable (w to the 1st power). Now multiply that equation by w and you should see your answer appear.

4. Brooke2013

is the answer C ? 5w^3 - w^2 - 4w; cubic trinomial

5. malical

I dunno. Can we give proof for why?

6. Brooke2013

Because that's what I got when I figured out the problem, I was just making sure it's right.

7. malical

That is correct.

8. Brooke2013

Alright Thank you :)