Hello!
The interior angles of every triangle add to equal 180 degrees. With that, you can add all angle expressions and set them to equal 180 to find x:
180 = 2x + 50 + x + 46 + 3x
180 = 6x + 96
84 = 6x
14 = x
Now, substitute 14 for x in each expression to find the value of each angle:
2x + 50 => 2(14) + 50 => 28 + 50 => 78
x + 46 => 14 + 46 => 60
3x => 3(14) => 42
Let's check our work:
180 ? 78 + 60 + 42
180 = 180 <--True
Angle A = 42 degrees
Angle B = 78 degrees
Angle C = 60 degrees
Hope this helps!