$A$ is nonsingular whenever $x\neq 8$.
Work Step by Step
$A$ is singular if $$ad-bc=0 \Longrightarrow 8-x=0\Longrightarrow x=8. $$ Then $A$ is nonsingular whenever $x\neq 8$.
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.