Your answer would be 154*. Reason being, if there are two parallel lines and a line running through them, you will only have 2 types of angles. The labeled 154* tells us that the angle to its right would be 26 degrees. Making line m = to 180 degrees at that angle. Then if you did the same thing with line t, you would get angle x to be equal to 154 degrees.
It is complicated like that, or as simple as just taking the 154 and saying that x has the same angle. Due to the fact that both angles are adjacent, they are the same.