Answer :
[tex]\text{Use}\\\\a^0=1\ \text{for}\ a\neq0\\\\a^{-n}=\dfrac{1}{a^n}\ \text{for}\ a\neq0\\----------------------------\\\\-(14x)^0y^{-7}z=-1y^{-7}z=-1\cdot\dfrac{1}{y^7}\cdot z=\boxed{-\dfrac{z}{y^7}}\\\\for\ x\neq0\ \wedge\ y\neq0[/tex]
[tex]\text{Use}\\\\a^0=1\ \text{for}\ a\neq0\\\\a^{-n}=\dfrac{1}{a^n}\ \text{for}\ a\neq0\\----------------------------\\\\-(14x)^0y^{-7}z=-1y^{-7}z=-1\cdot\dfrac{1}{y^7}\cdot z=\boxed{-\dfrac{z}{y^7}}\\\\for\ x\neq0\ \wedge\ y\neq0[/tex]