Question 1144879
<pre>He sold the computer at 140% (profit of 40%, add to 100%) of what he paid but
he sold the guitar for only 90% (loss of 10%, subtract from 100%) of what he
paid. Let C and G stand fot the costs.  Change the percents to decimals. He
sold them both for $500+$110 or $610.

{{{system(C+G=500,1.40C+0.90G=610)}}}

Clear the decimals, solve by substitution or elimination. You finish.

Edwin</pre>