First, y = 40, since they are vertical angles.
Second, I assume the two angles with red marks are the same measure. The notation I learned would put a tick mark to formally indicate that, but without those being the same, you couldn't answer the question.
So, assuming that's correct, you'd have 2x + 2x + 40 = 180, since the measures of the angles of the left triangle have to add to 180º.
Solving 2x + 2x + 40 = 180, you'd get 4x = 140, or x = 35º.
Hope that helps.
