Q83. Let $A$ be a square matrix of order 2 such that $| A | = 2$ and the sum of its diagonal elements is - 3 . If the points $( x , y )$ satisfying $\mathrm { A } ^ { 2 } + x \mathrm {~A} + y \mathrm { I } = \mathrm { O }$ lie on a hyperbola, whose length of semi major axis is $x$ and semi minor axis is $y$, eccentricity is e and the length of the latus rectum is $l$, then $81 \left( e ^ { 4 } + l ^ { 2 } \right)$ is equal to