Hey! Let me help you with this problem:
We know that segment XZ is a line, and we also know that segment QY intersects that line.
The most important part of this problem boils down to the concept that angles on a straight line add to 180o. Because QY is a segment that creates two different angles, these add up to 180o. These angles are (10a + 2) and (5a-2), so we can make the equation:
(10a + 2)o + (5a - 2)o = 180o
After combining like terms...
15ao = 180o, so a = 12o
The problem asks for m<XYQ, so plug in a = 12o into (10a + 2) to get 122o