So for this equation we're going to complete the square.
Firstly, what two terms have a product of 120x^2 and a sum of 29x? 24x and 5x. Replace 29x with 24x + 5x:

Next, factor 4x^2 + 24x and 5x + 30 separately. Make sure that they have the same quantity inside the parentheses:

Now you can rewrite the equation as:

Now using zero product property, solve for x:

In short, x = -1.25 and -6