Answer
The cost of the fax machine, including sales tax, is $396.05.
Work Step by Step
discount=rate*original
$d=(0.07)(398)=27.86$
sale price=original-discount
$s=398-27.86=370.14$
sales tax=rate*price
$t=(0.07)(370.14)=25.91$
total cost=price+tax
$tc=370.14+25.91=396.05$