Solve the simultaneous equation: 2x +y =18; x-y=6. (3)
- Turn x-y=6 into y=6+x.2) Insert y=6+x into 2x+y=18; get 2x+6+x=183) Turn the latter equation into 3x=18- 6=124) Divide 12 by 3 to get x=45) Insert x=4 into y=6+x into y=106) Conclude with x=4 and y=10
