|-10|-|4-13|

$$\left | x \right |=\sqrt{x^2}$$ for any real number x

So: $$\left | -10 \right |-\left |4-13 \right |\\
=\left | -10 \right |-\left |-9\right |\\
=\sqrt{(-10)^2}-\sqrt{(-9)^2}\\
=\sqrt{100}-\sqrt{81}\\
=10-9\\
=1$$

10-9=1  that is the answer