What is the difference between the roots of $x^2-14x+24=0$?

For $x^2-14x+24=0$, the discriminant is $D=b^2-4ac=(-14)^2-4(1)(24)=196-96=100$. The roots are $\frac{14\pm\sqrt{100}}{2}=\frac{14\pm10}{2}$, so they are 12 and 2. Their difference is $10$.