Move all terms to one side.
\[18+3x-{x}^{2}=0\]
Multiply both sides by \(-1\).
\[{x}^{2}-3x-18=0\]
Factor \({x}^{2}-3x-18\).
Ask: Which two numbers add up to \(-3\) and multiply to \(-18\)?
Rewrite the expression using the above.
\[(x-6)(x+3)\]
\[(x-6)(x+3)=0\]
Solve for \(x\).
Ask: When will \((x-6)(x+3)\) equal zero?
When \(x-6=0\) or \(x+3=0\)
Solve each of the 2 equations above.
\[x=6,-3\]
\[x=6,-3\]
x=6,-3
