Answer
$6\text{ pieces}$
Work Step by Step
Substituting $p=11$ in the given equation, $
p=-x^2+47
,$ results to
\begin{array}{l}\require{cancel}
11=-x^2+47
\\
x^2=47-11
\\
x^2=36
.\end{array}
Taking the positive square root of both sides (since $x$ is nonnegative), the equation above is equivalent to
\begin{array}{l}\require{cancel}
x=\sqrt{36}
\\
x=6
.\end{array}
Hence, the demand for the scissors, $x,$ is $
6\text{ pieces}
.$
