You need to get that binder but the door to the office has an electronic lock which requires a four-letter password. Curiously, posted on the wall next to the door is a sheet of paper with the message: "To enter, find the tangent lines, then follow them to the -axis. You should always land on an integer between 1 and 26." Immediately below the message you see: x2 - 20x + 68 20x + 36 - 20x + 28 x2 - 60x + 756 at x = 12 at x = 26 at = = 4 at x = 18