Jackie got (4, -2) as her solution to a linear system. She was checking the solution in the first equation, 2x - y = 6. She decided that (4, -2) did work in that equation, and she was getting ready to check the second equations. Her friend was doing the same problem and told Jackie she had made an error when doing the check. The friend is correct. What mistake did Jackie most likely make that would cause her to think (4, -2) was the solution? <3 Thank you