Answer:
x = 100
Step-by-step explanation:
[tex]57 \degree + (x + 23) \degree = 180 \degree..(straight \: line \: \angle s) \\ (x + 80) \degree = 180 \degree \\ x + 80 = 180 \\ x = 180 - 80 \\ \huge \red{ \boxed{x = 100}}[/tex]
x = 100°
57° + 23° = 80°
180° - 80° = 100°
look at my previous answer to another person who posted this same question if you want a more detailed version
