How to subtract a percentage & number?

hey guys just another question.
how would i go about subtracting a percentage and a number?
i have formated the number as currency($) and the percentage as percentage(%)
the 2 numbers are from seperate cells.
eg: $689.00 - 30.00%
when i try it, "=A1-B1" it equals to 688.20
the two numbers are also vlookups

thanks guys =)

So you want to subtract 30% of A1 from A1?

Try:

=A1-A1*B1