Chapter 3 - Section 3.2 - Problem Solving and Business Applications Using Systems of Equations - Exercise Set - Page 205: 18

$x=10000,y=20000$

Given: $x+y=30000$ and $0.14x-0.06y=200$ After plugging the variable $x$ form the first equation in the second equation, we get $0.14(30000-y)-0.06y=200 \implies -0.20y=-4000$ or, $y=20000$ Now, $x+20000=30000$ or, $x=30000-20000=10000$ Thus, $x=10000,y=20000$