Answer:
The exterior angle is equal to 77°
Explanation:
We know that all three angles of a triangle are equal to 180°. We also know that the exterior angle and its adjacent angle are equal to 180°.
1) We can find the angle adjacent to the exterior angle is 180-(3x+23), we can simplify this and get 157-3x for that angle.
2) We can create the equation 4x-15+2x-16+157-3x=180. After simplifying we get 3x+126=180.
3) To solve for x we can subtract 126 from both sides, 3x=54. We can divide 3 from both sides to isolate x, we get x=18.
4) Substitute the x value into the given term for the exterior angle, 3(18)+23
5) After simplifying you get 77