I think it’s 29. I’m not sure but because they’re on a straight line that’s 180 degrees the equation is simple to figure out: 4x+x+35 = 180. Combine like terms, 4x and x, and then you get 5x+35 = 180. Subtract 35 from both sides. Now you have 5x = 145. Divide both sides by 5 to isolate x. That’s how I got x =29.