Answer:
x = 80°
Explanation:
You want the value of x given a pentagon with two angles marked with expressions in x.
Sum of angles
The sum of interior angles in an n-gon is 180° × (n -2). For the 5-sided figure shown, the sum of angles is 180° × 3 = 540°.
Using this value, we have ...
(x +40°) +125° +(x +5°) +(x +50°) +80° = 540°
3x +300° = 540° . . . . . . simplify
x +100° = 180° . . . . . . . divide by 3
x = 80° . . . . . . . . . . . . subtract 100°
The value of x is 80°.