Quadratic expressions are <em>mathematical expressions</em> that have the <u>power</u> of one of its <em>alphabets</em> being <em>equal to</em> and <em>not more</em> than two. The given <em>expression</em> in the question can be <u>simplified</u> as 81 + 162 - 45 - 54x - 112
<u>Algebraic</u> expressions are <em>mathematical expressions</em> that consist of given <u>number(s)</u> and <u>alphabet(s).</u> When the power (exponential) of one of the <u>alphabets</u> is given as two, then the <em>expression</em> can be classified as a quadratic expression.
Thus the given <u>expansion</u> of the <em>quadratic expression</em> can be simplified as follows: