Answer
$280$
Work Step by Step
Using order of operations, the given expression, $(10\cdot8-9\cdot7)^2-54\div9-3,$ simplifies to
\begin{align*}\require{cancel}
&
(80-63)^2-6-3
\\&=
17^2-6-3
\\&=
289-6-3
\\&=
283-3
\\&=
280
.\end{align*}
Hence, the expression $(10\cdot8-9\cdot7)^2-54\div9-3$ simplifies to $280$.
