Simplify I came up with 5.5

(15x^5-21x^4+21x^2)/(3x^2 )

not sure if I did this the correct way it just doesn't seem right at all.

divide each term by 3x^2

5x^3 -7x^2+7

check that.

To simplify the given expression, you need to divide each term in the numerator by the denominator. Remember, when dividing like terms, you subtract their exponents.

Here's how you can simplify the expression step by step:

1. Divide each term in the numerator by the denominator:
(15x^5)/(3x^2) - (21x^4)/(3x^2) + (21x^2)/(3x^2)

2. Simplify the coefficients:
(5x^5) - (7x^4) + (7x^2)

Now, the expression is simplified as (5x^5 - 7x^4 + 7x^2).

It's important to note that if you're unsure whether you simplified the expression correctly, you can always distribute your expression back into its factored form to check. In this case, if you expand (5x^5 - 7x^4 + 7x^2) * (3x^2), you should arrive at the original expression:

(5x^5 - 7x^4 + 7x^2) * (3x^2) = 15x^7 - 21x^6 + 21x^4.

So, your simplification is correct: (5x^5 - 7x^4 + 7x^2).