If 2x-4y=14, then we know that 2x=14+4y. This means that x=7+2y. If we substitute this into the next equation we get: 3y+(35+10y)=9. This means that we have 35+13y=9. If we subtract 35 from both sides we get 13y=-26. This means y=-2. If you subsitute this in the first equation, we have 2x--8=14. -- means + so you do 2x+8=14. This means that x=3.
