x cubed + x squared over x squared - 16 times x + 4 over 3x to the fourth power + x cubed - 2x squared.

i got x + 1 over (x-4) (x+1) (3x+2).
is this correct?

now cancel your x+1 and you got it...

actually I got over 1/(x-4)(3x-2)...slightly different.

oh. i re-did the problem and got that- i got the signs confused and forgot to cancel the x+1 before... thanks

To simplify the given expression, let's break it down step by step:

1. First, let's simplify the numerator and denominator separately.
Numerator: x^3 + x^2
Denominator: x^2 - 16

2. The numerator can be factored by taking out the common factor x^2:
Numerator: x^2(x + 1)

3. Similarly, the denominator is a difference of squares, so it can be factored:
Denominator: (x - 4)(x + 4)

4. Next, let's simplify the second part of the expression:
(x + 4) / (3x^4 + x^3 - 2x^2)

5. For this part, it is advisable to factor out the highest common factor, which in this case is x^2:
(x + 4) / (x^2(3x^2 + x - 2))

6. Now, let's factor the quadratic expression:
(x + 4) / (x^2(3x^2 + 3x - 2x - 2))

7. Continuing to factor, we have:
(x + 4) / (x^2(x(3x + 3) - 2(3x + 1)))

8. Further simplifying:
(x + 4) / (x^2(x(3x + 3) - 2(3x + 1)))

9. Combining like terms:
(x + 4) / (x^2(x(3x + 3) - 6x - 2))

10. Simplifying:
(x + 4) / (x^2(3x^2 + 3x - 6x - 2))

11. Continuing to simplify:
(x + 4) / (x^2(3x^2 - 3x - 2))

Therefore, the simplified expression is:
(x^2(x + 1)(x + 4)) / (x^2(x - 4)(3x^2 - 3x - 2))

So, the expression you got, x + 1 / (x - 4)(x + 1)(3x + 2), is not correct.