$P_{1}=8KNP_{2}\text{ and }8KNP_{2}=10KN$

$\left\{\begin{matrix}P_{2}=\frac{P_{1}}{8KN}\text{, }&P_{1}=10KN\text{ and }N\neq 0\text{ and }K\neq 0\\P_{2}\in \mathrm{R}\text{, }&\left(K=0\text{ or }N=0\right)\text{ and }P_{1}=0\end{matrix}\right.$

$\left\{\begin{matrix}P_{1}=0\text{, }&N=0\text{ or }K=0\\P_{1}=10KN\text{, }&P_{2}=\frac{5}{4}\end{matrix}\right.$