Chapter 4 - Section 4.2 - Solving Systems of Linear Equations by the Substitution Method - Exercise Set - Page 300: 26

{(2000,1000)}

x+6y=8000 x+6y-6y=8000-6y x=8000-6y Plug this value for x into the other equation. 0.3x-0.6y=0 10(0.3x-0.6y)=10(0) 3x-6y=0 3(8000-6y)-6y=0 24000-18y-6y=0 24000-24y=0 -24y=-24000 y=$\frac{-24000}{-24}$ y=1000 Plug this value for y into the first equation to find x. x=8000-6(1000) x=8000-6000 x=2000 Therefore the solution is {(2000,1000)}