Sue the high school hacker gets paid $150 for installing Linux on
her dad's company's web server, and invests it all in stock in a
startup that goes up 17% before she sells. She then earns $72 for
helping recover a file from a disk that crashed without any backups.
At this point she invests all her money in Microsoft, just in time for
the Great Crash of 1997 in which she loses 54% of her investment.
Write a Scheme expression that calculates how much money Sue ends
(* (- 1 0.54)
(* (+ 1 0.17)