Answer:
x = 21°
Step-by-step explanation:
Consider the lines m and n. It's given that they're parallel to each other.
Now, the angles 123° and (5x+18)° can be considered as alternate interior angles, as they lie on opposite sides of the transversal. Thus, they will be equal.
Now all we have to do is solve the equality.
123 = 5x + 18
123-18 = 5x
5x = 105
or x = 21°
There you go, hope this helps!
