Answer:
$640
Step-by-step explanation:
Let [tex]x[/tex] equal the original price of the machine.
We know that $64 is 10% of [tex]x[/tex] because $64 is left of [tex]x[/tex] after the 90% reduction.
Set up an equation:
[tex].10x=64[/tex]
Divide by the coefficient of [tex]x[/tex], which in this case is [tex].10[/tex]
[tex]x=640[/tex]
