## Thomas' Calculus 13th Edition

$$-16$$
We know that $$div F=\dfrac{\partial P}{\partial x}i+\dfrac{\partial Q}{\partial y}j$$ From the given equation, we have $div F=-1-1=-2$ The volume of the cube is: $$div F=\iiint_R (-2) dA \\=(-2)[(2)(2)(2)] \\=-16$$