[tex]\huge\boxed{\$64}[/tex]
Start by writing a formula, where [tex]x[/tex] is Brad's purchase price and [tex]y[/tex] is the original price.
[tex]40=8+\frac{y}{2}[/tex]
Subtract [tex]8[/tex] from both sides.
[tex]32=\frac{y}{2}[/tex]
Multiply both sides by [tex]2[/tex].
[tex]\boxed{64}=y[/tex]