Respuesta :

Answer:

x = 100

Step-by-step explanation:

180-57 would equal 123 which means 123 = x +23 and you can simplify this equation by moving 23 over to 123 and subtracting them leaving x = 100

123 = x+ 23

-23 + 123 = x

100 = x

x = 100

sorry, i'm really bad at explaining

180 degree angles when added

180-57 (for known angle)= 123

x+23=123<- we need to take off the all known angles to get x

123-123=100

x=100 is the answer