Chapter 8 - Systems of Linear Equations and Problem Solving - 8.2 Solving by Substitution or Elimination - 8.2 Exercise Set - Page 516: 29

$(7,-2)$

Terms containing $y$ are opposite in the additive sense. Add the equations: $ 4x=28\qquad$ ... and solve for $x$ $x=7$ Substitute into one of the initial equations: $x-2y=11$ $7-2y=11$ $7-11=2y$ $-4=2y$ $y=-2$ Form an ordered pair $(x,y)$ as the solution to the system $(7,-2)$