Answer:
x = 11°
Explanation:
You want to know the value of x given a triangle with exterior angles 147°, 4x, and an interior angle of x at the third vertex.
Setup
The exterior angle of the triangle at B is the supplement of x: 180°-x. The sum of the exterior angles of a polygon is 360°, so we have ...
147° +4x +180° -x = 360°
Solution
Collecting terms, we have ...
327° +3x = 360°
3x = 33° . . . . . . . . . subtract 327°
x = 11° . . . . . . . . . . divide by x