[tex]\bf -\cfrac{1}{4}(vq^4)(-8v^3q)^2\implies -\cfrac{1}{4}(vq^4)\stackrel{\textit{distributing the exponent}}{[(-8)^2v^{2\cdot 3}q^2]}\implies -\cfrac{1}{4}(vq^4)(64v^6q^2) \\\\\\ -\cfrac{1}{4}(vq^4 64v^6q^2)\implies -\cfrac{64}{4}(v v^6 q^4q^2)\implies -16v^{1+6}q^{4+2}\implies -16v^7q^6[/tex]
