It cannot be factored in the set of integers. 

However, you can factor in R (the set of real numbers).

If you solve the equation:

You can find the real roots (Click here to see the step by step solving for the quadratic equation)

And then the factoring is done by the formula:

3w^2 - 15w - 50 = 3(w - w1)(w - w2)

That is, if we plug the values for 'w1' and 'w2':