Х^2-9/3х^2+х^2

To simplify the expression (x^2 - 9) / (3x^2 + x^2), we can first combine like terms in both the numerator and denominator:

In the numerator: x^2 - 9

In the denominator: 3x^2 + x^2 = 4x^2

So the expression becomes:

(x^2 - 9) / (4x^2)

Now, let's factor the numerator:

x^2 - 9 = (x - 3)(x + 3)

The expression can be rewritten as:

[(x - 3)(x + 3)] / (4x^2)

This is the simplified form of the expression (x^2 - 9) / (3x^2 + x^2).