simplify the rational expression

3x^2+6x / x^2-16

To simplify the rational expression (3x^2 + 6x) / (x^2 - 16), we can factor the numerator and denominator as much as possible and then cancel any common factors.

Factoring the numerator:
3x^2 + 6x = 3x(x + 2)

Factoring the denominator:
x^2 - 16 = (x + 4)(x - 4)

The rational expression can now be written as:
(3x(x + 2)) / ((x + 4)(x - 4))

Now, we can cancel out common factors.
Removing the common factor of (x + 2) in the numerator and denominator, we get:
(3x) / ((x + 4)(x - 4))

Therefore, the simplified form of the rational expression (3x^2 + 6x) / (x^2 - 16) is:
(3x) / ((x + 4)(x - 4))