Okay, I will give you the building blocks for solving this equation.
Now something you will need to remember is that a triangle will always add up to 180 degrees.
We can use y as that one unknown side in the triangle.
Knowing this, we can say (9x+16) + (6x+15) + y = 180
Then we can combine like terms like so : 15x+31+y = 180
There are two variables though. So we need more information.
Well, turns out we have the exterior angle of a straight line and the angle measures of a straight line must equal 180. We can now use (19x+3) + y = 180.
With both of these equations, you can now solve and find both of the angles