Question

X+2y=14
Y=3x-14
Substitution

Answer 1

X+2y=14, okay so you have to write X+2(3x-14)=14

Answer 2

`\left \{ {{x+2y=14} \atop {y=3x-14}} \right.\\\\Substitution\\\\ x+2(3x-14)=14\\ x+6x-28=14\\ 7x-28=14\ \ \ | add\ 28\\ 7x=42\ \ \ | divide\ by\ 7\\x=6\\ y=3x-14=3*6-14=18-14=4\\\\Solution:\\ \left \{ {{y=4} \atop {x=6}} \right.`