Domain of a Function

State the domain of the following:\[
        y= \frac{2x-5}{x+4}
    \]

 State the domain of the following:\[
        y=\frac{2x-9}{x^3+2x^2-8x}
    \]

State the domain of the following:\[y = \frac{\sqrt[3]{x}}{\sqrt{2x-6}}\]

Find the domain of the following function:\[
       f(x)= \sqrt{x^2-5x+6}
    \]